Short Range Radio Device Communications Short Range Radio Device CommunicationsIonising radiation and health hazards Ionising radiation and health hazards Radio transmission An electric current in a straight conductor produces a circular magnetic The majority of Irish homes get Internet access via wireless routers. fi eld which gets weaker with distance. An alternating current produces Communication between a wireless router and any smart connected Radios and TVs pick up and process radio waves, i.e., electromagnetic an alternating magnetic fi eld. But does this fi eld appear the instant the device is bidirectional. Both devices contain a transmitter and a receiver waves typically ranging in frequency from 30 Hz to 30 GHz. Such current starts or does it take time to travel? and so can ‘talk’ to one another. The communication is complex and the broadcasts require high power transmitters. Most of the RTE radio data rate is very high (e.g. 600 Mbps). Each device can detect errors In the 1850s James Clerk Maxwell began to consider such questions. transmittersWhat operate is atradiation? 200,000 watts (i.e. 200 kW) while the power of Main kinds of ionising λ (m) E (eV) inMain the received sources packets of ofionising data and ‘request’radiation that be sent again. At the some local radio transmitters may be as low as 10 watts. He produced a very comprehensive theory of electromagnetic waves same time the router may be communicating with several other local and calculatedradiation that they should travel at a speed of approximately1 pm 1.24 GeV The pie-chart below shows the average contribution from different sources A candle radiates light and heat in all directions and can devicesof ionising and radiation with remote to the averagecomputers Irish via person. the worldwide makes web. the biggest In Ireland (as in most countries) a person must obtain a licence for radio 300,000,000The diagram metres shows per the second. This led him to propose that light was in Radon illuminate a room. From its source the light appears to travel 10 pm 124 MeV contribution and is the cause of about 250 lung cancer cases each year in ComReg is the statutory body responsible for the regulation transmission. The type of licence depends on the application (mobile wavelength and energy of Wireless routers use 2.4 GHz and 5 GHz bands (2400 MHz & 5000 in straight lines, called rays, and if something blocks the path fact an electromagnetic wave. Ireland. Radon is a radioactive gas that typically seeps into houses from the of the electronic communications sector (telecommunications, phone, amateur radio, air traffi c services etc.). The licence specifi es the electromagnetic waves on a 100 pm 12.4 MeV MHz). As the word ‘band’ implies, each of these is not single frequency a shadow is formed. Light is a form of radiation. scale; photons on ground. It is a product of the radioactive decay of naturally occurring radiocommunications and broadcasting transmission) and maximum power and the frequency ranges or ‘bands’. Maxwell’slogarithmic theory (1867) described the propagation rays Gamma of electromagnetic1 pm 1.24 MeV but a range of frequencies that is divided into several ‘ ’. uranium or thorium. Since 1998, all new buildings in high channelsradon areas must the postal sector. Its remit covers all kinds of transmission wavesthe — next including step up radio have waves.ten times Twenty years later Heinrich Hertz fi rst A dual-band router can use both of these bands. The diagram shows However,When no licence sunlight is isrequired dispersed for bycertain a prism transmissions a spectrum isthat formed we take as Newton more energy and may cause ten 10 pm 124 keV have a radon barrier installed and, in other areas, a standby radon sump networks including: demonstrated the propagation of radio waves. how— a thetype 2.4 of fanGHz that band draws is airdivided from underinto 14 the channels, floor and manyvents it of to which the outside. for grantedfound today. in 1665. For instance, In 1800 Thomas a mobile Young phone showed must that be lightable was to transmitsome kind of times more ionisations. Note that 100 pm 12.4 keV The EPA’s Office of Radiological Protection (ORP) is overlap;Both methods each canband be is used 22 MHzto reduce wide. radon A router entering can the send building. large amounts • Traditional telephone wire wave and he measured the wavelength of light of different colours; they the term ‘gamma ray’ refers to X-rays responsible for ensuring that people and the radio signals as well as receive them. Mobile phones operate in specifi c • Television and radio frequencies range from about 750 nm (red) to about 400 nm (violet). eselectromagnetic o eectromagnetic radiation coming aves 1 nm 1.24 keV of data very quickly by using several channels at the same time. radio frequency bands and their power is less than 0.4 W. radiation Ionising environment in Ireland are protected from the harmful It is very easy to reduce the radiation dose from radon by reducing the levels of • Radiocommunications including fi xed wireless Also in 1800 Herschel discovered, using a thermometer, that the spectrum A conductorfrom atomic carrying nuclei; a theycurrent are alternating 10 nm 124 eV radon in the home. There is little that we can do to reduce our exposure to other effects of ionising radiation.

A smart phone may also have WiFi capability, that is, it uses a specifi ed otherwise identical with high UV • Mobile operators providing voice and data services contained some heat radiation in the dark area beyond the red; we now callone million times per second (i.e. at 100 nm 12.4 eV sources of ionising radiation such as gamma rays, cosmic rays and radiation communicationsthis infra-red protocol radiation and (IR).transmits The following radio signals year (1801) at low Ritter power showed that one megahertzenergy X-rays. or 1 MHz) radiates from the buildings we inhabit, the food we eat and indeed from our own bodies. The ORP• isSatellite a successor services to the Radiological Protection (generally less than 0.1 W). WiFi therefore has a short range ― typically 1 µm 1.24 eV Institute of Ireland which merged with the EPA in 2014. there was some form of radiation beyond the violet end of the spectrum electromagneticThe kinetic energywaves whoseof alpha wave Visible less than which100 metres. could cause chemical change faster than any of the visible colours. lengthparticles is 300 metres.is generally At abetween frequency of 10 µm f (Hz) Measurement of ionising radiation ComReg enables competition in the communications sector It is called ultra-violet radiation (UV). IR 300 MHz5 and the 7 MeV wavelength while that would of beta be just The first thing to decide is what exactly to measure. by facilitating market entry for networks and services and 100 µm 3 THz Source: Wikipedia List of Wlan Channels hat are SRDs 3 metres.particles The generally higher the ranges frequency, from the Theby keyregulating functions access of the to ORP networks are: so as to ensure that 100 keV to 20 MeV. However the 1 mm 300 GHz Option 1: How radioactive is a piece of material; i.e., how many nuclear Today SRDsWhat or ‘short is ionising range (radio) radiation? devices’ are in common use. Below shorter the wavelength. (Their product is consumers, both business and residential, have choice in energy of cosmic rays may be −1 disintegrations occur in it every second. • Educating the public on the risks of ionising are some examples, together with their allocated frequencies: 300,000,000, i.e. the speed of light in m s .) 10 mm 30 GHz Bluetooth is a lower power, bidirectional wireless communication system We now know that visible light, IR and UV form a small part of a much thousands of times greater but Unit: becquerel (Bq); 1 Bq = 1 disintegration per second the radiationservices which they wish to use. In a rapidly evolving wider spectrum of electromagnetic waves. Those with shorter wavelengths is commonly about 300 MeV. 100 mm 3 GHz that also uses the 2400 MHz band but divides it into 79 channels, each of The table shows the part of the Non-ionising radiation This does not indicate how much radiation a person might sector, both in technological and commercial terms, ComReg • wireless local area networks (WLANs) including Wi-Fi Microwaves which is just 1 MHz wide or 40 channels that are 2 MHz wide. Bluetooth • Contributing to Government policy on radiation transmit more energy and often interact with matter as particles called electromagnetic spectrum used by SRDs. 1 m 300 MHz absorb; gamma rays would be much less likely to be absorbed provides the framework for the introduction of new services 5 bands in range: 2.4 − 5.9 GHz divides the data to be transmitted into packets that are sent on different protection matters photons. than alpha or beta particles. such as next generation mobile to support smartphones • Bluetooth devices 2.4 − 2.4835 GHz Non-ionising 10 m 30 MHz channels. The receiving device reassembles the data in the correct order. Option 2: Measure the amount energy absorbed per kilogram due to Electromagnetic radiation whose wavelength is less than about 300 nm Radio The maximum transmission speed is 50 Mbps and the range is typically • andLicensing similar applications. and regulating the possession and use • car isdoor called openers, ionising automatic radiation because gates it can knock electrons off433 some MHz atoms radiation 100 m 3 MHz radiation; this is the ‘absorbed dose’. of ionising radiation in medicine, industry, research How can electromagnetic waves carry about 10 metres. Bluetooth applications include: −1 • babyand alarms molecules causing ions to form, or to be more precise, ion2.4 pairs. GHz Ionising The boundary between ionising 1 km 300 kHz Unit: gray (Gy): 1 gray = 1 joule per kilogram (1 J kg ) Encouragingand education innovation is also a key role for ComReg. This radiation can damage bio-molecules such as DNA, causing cells to die information? For example, an FM radio • wireless microphones 5 bands in range: 470 MHz − 1800 MHz and non-ionising radiation is not • smart watches, headphones, earbuds, home audio systems or malfunction. station (e.g. RTE Radio 1 on 88.5 MHz) 10 km 30 kHz Option 3: A calculated measure of the potential damage to body tissues • coversMaintaining both regulatory a national innovations, laboratory forsuch the as implementation universally agreed but is often Radio waves • hands-free mobile phone answering (in car) • RFID tags (Radio Frequency Identifi cation) 13.56 MHz transmitstaken a to RF be signal100 nm centred, (i.e. with in this due to radiation. of marketmeasurement reviews of under radioactivity the new levels European in the regulatory case, on 88.5 MHz. Its frequency • printing from mobile devices (phone, tablet etc.) • Near-fiIonising eld communication particles (NFC) 13.56 MHz photon energy of about 12 eV). Unit: sievert (Sv): 1 sievert = 5.5% risk of developing cancer as a result framework,environment and technical innovations. On the radio spectrum is variedRadiation or ‘modulated whose wavelength’ continuously is greater to matchthan that the is variationclassed as in non-ionising the • transferof ofradiation images exposure. from digital Repeated cameras. doses of 1 Sv over minutes or side the role involves development of strategies for • Where appropriate, to provide, or oversee the These devicesIn the 1890suse low certain power materials RF (radio were frequency) found to emit in specifia form edof highly RF ionising audioand signal includes that itUV-C ‘carries’., UV-B An, UV-A FM ,radio visible (receiver) light, infrared, detects microwaves, the ‘carrier radio’ hours would be likely to lead to death within a few weeks. management and use of the radio spectrum, new initiatives in radiation which, unlike light, was strongly affected by a magnet and so was (i.e. thewaves RF andsignal) very and low generatesfrequency radio an audio waves signal from power from thelines variation (50 Hz). in he uture and the nternet o hings provision of, specialist radiation protection services bands. They are not likely to cause harmful interference to other networks The sievert represents the biological effect of an absorbed dose. It is derived the wireless licensing area, and the promotion of Ireland as a different from electromagnetic waves. Some materials emitted positively such as personal dosimetry, radioactivity or to essential public services and so no licence is required for their use. its frequency.The fact that The they communication may not cause is ionisation in one direction does not only. mean that these Thefrom rapidly the gray expanding but employs use a weightingof SRDs thatenables varies many with the domestic type of radiation:and charged particles called alpha particles. Others emitted negatively charged testmeasurement, bed for innovative instrument uses ofcalibration, the spectrum radon (See Test & Trial radiations are always harmless. In large doses they can cause body commercial devices to communicate with one another. This ‘Internet of particles, or beta particles. Some materials also emitted high energy 1 Gy of gamma rays, X-rays or beta particles = 1 Sv Irelandmeasurements at www.testandtrial.ie). and product certification hat are eectromagnetic aves SRDstissues to heat up faster that blood flow can dissipate the heat. Sunbathing things’ (IoT) with embedded communications technology brings with it electromagnetic waves called gamma rays. All these materials are said can cause sunburn. Even with sunscreens the skin is damaged; the 1 Gy of alpha particles = 20 Sv We take lightto be for radioactive granted. .At the fl ick of a switch we can turn on an A ireess car door e contains an RF transmitter; when activated it the possibility of so-called smart homes, intelligent transportation and • Assisting in the development of national plans tanning process is the body’s reaction to DNA damage in skin cells. 1 Gy of protons = 2 Sv ComReg’s expertise in the wireless sector is widely electric lamp. The shape of shadows lead us to think that something is transmits a signal that carries a unique digital code. A receiver in the car smart cities. Appropriate standards and operating protocols are being to deal with nuclear accidents and incidents In 1912 Victor Hess found — ascending above 5000 metres by balloon — that Exposure to UV-A can lead to skin cancer. recognised. In the recent past ComReg has chaired the high coming from the lamp and it seems to travel in straight lines. We can pick up and decodes the signal and if the code is correct it responds by developedThe average to radiation help support dose receivedthe various by people IoT uses in Ireland mentioned each year above. is about It is extremely ionising radiation increased with altitude and that it did not come four millisieverts; 0.004 Sv = 4 mSv = 4000 µSv (microsieverts). However, • levelConducting advisory group and promoting to the European research Commission, on a range the Radio refl ect light with a mirror and refract it with a lens. locking or unlocking the doors. This communication is in one direction. estimated that by 2020 there will be around 50 billion connected devices from the Sun. This cosmic radiation comes from outside our solar system some people receive ten times that dose due to high radon levels in their Spectrumof areas Policy relevant Group, to radiation as well protectionas the Body of European and at least some of it is extra-galactic It is by far the most strongly ionising In 1678 Christiaan Huygens explained the properties of light in terms of RDs, on the other hand, use bidirectional communication. RFID tags 1homes. The greater the dose, the greater the risk. Regulators for Electronic Communications. In addition, for the radiation known. About 90% of it consists of protons, often travelling at over According to ComReg in its key quarterly report for Q2 2016 there were 1,330,946 fi xed • Driving forward programmes of radon waves of some sort. In 1690 Isaac Newton tried to explain the properties do not have batteries and are powered by the RF signal that is sent from broadbandA radon test subscriptions kit can be (an obtained increase from of 0.7% the EPA,from Q1 Office 2016 andof Radiological an increase of 3.9% second year in a row, ComReg was awarded the Business 99% of the speed of light. It also contains alpha particles and lesser amounts measurement and remediation in homes, of light in terms of little particles or ‘corpuscles’ as he called them. the tag reader. The tag responds by sending the required information comparedProtection. to Q2It contains 2015). Most sealed such plastic subscriptions film which rely on is theleft usein placeof wireless for 30 routers. days of heavier nuclei, neutrons and positrons. in Excellenceworkplaces for and Research schools and Development for its Test However, around 1804 Thomas Young demonstrated diffraction and which is picked up and decoded by the reader. In contrast to barcodes, and then returned to EPA. When the film is developed the level of radiation is The speed of a wave is equal to the and Trial Ireland service. That award honours the valuable interference of light — properties that are characteristicf = c/λ of waves. The RFIDs do not require line of sight. For example, a hand held RFID reader indicated by the number of tracks left on it by ionising radiation. • Representing Ireland on international bodies frequency (f) multiplied by the wavelength Reguation contribution and difference that ComReg makes to wireless wave theory of light was then universally accepted. But nobody knew what can scan up to fi fty items of clothing on a shelf in one second and record dealing with radiation protection and nuclear (λ). For electromagnetic waves this is E = hf all their details. Some RFID tags contain memory chips and can be In Ireland, the technical criteria for the operation of SRDs on a innovation in Ireland. was actuallywritten waving. as c=f.λ where c is the speed. Common radiation doses and risk matters E = hc/λ joules updated by the tag reader. The following are some applications of RFIDs: licence-exempted basis is set out in ComReg document 02/71R9 Find out more about the work of ComReg at www.comreg.ie In 1831 MichaelRearranging Faraday this equationdiscovered we getelectromagnetic f = c/λ. induction, i.e the The accompanying table lists some ‘Thoron’ is a (www.comreg.ie/media/dlm_uploads/2015/12/ComReg15131.pdf1 Dental X-ray 5 μSv) • Cooperating with radiation protection authorities E = hc/eλ electron volts • Identifi‘Radon ’cation refers to of goods entering of leaving a premises generationThe of energyelectricity per photonusing a is magnet given by and E = ahf conductor.= Faraday thought traditional name for averageand all SRDsradiation placed doses on commonly the Irish market are required to comply with this. and other relevant organisations overseas. radon 222 (222 Rn). 1 Dublin-London return flight 8 μSv radon 220 (220 Rn). received by people in Ireland. Radon that light mighthc/λ, where have Eelectrical is the energy or magnetic in joules ,properties f is and after years of • PersonalIt is a decay identity product tags with access control It is a decay isIn clearly Europe, the themost radio significant spectrum requirements for SRDs are being trial and errorthe frequency he was eventuallyin hertz and successful. h is Plank’s He published his fi ndings the of uranium 238 (238 1 Chest X-ray 20 μSv For further infromation visit: www.epa.ie/radiation −34 • Monitoring of runners at specifi ed points in a race product of thorium ind this and other essons on staie constant (6.6 × 10 J s). A useful alternative unit of energy for photons is U) with a half life of contributorconsidered to ourby anoverall expert radiation group of radio frequency managers. The following year (1845). This was a remarkable discovery. Indeed, many 232 (232Th) and has Annual cosmic ray dose 350 μSv the . It is found by dividing the energy in joules by the charge • Laundering3.8 days. of work clothing (and recording number washes) exposuregroup will but assist fortunately and advise it is the onone the future radio spectrum needs of IoT. people todayelectron would not volt expect light to be affected by a magnet. a half life of 55.6 Find this and other lessons on www.sta.ie −19 (There are over 30 that we can most easily avoid. on an electron, e (1.602 × 10 C). seconds. Annual radon dose (avg.) 2230 μSv isotopes of radon.) hort ange adio evice Communications Ionising radiation Short Range Radio Device Communications and health hazards Ionising radiation and health hazards adio transmission An electric current in a straight conductor produces a circular magnetic The majority of Irish homes get Internet access via wireless routers.1 fi eld which gets weaker with distance. An alternating current produces Communication between a wireless router and any smart connected Radios and TVs pick up and process radio waves, i.e., electromagnetic an alternating magnetic fi eld. But does this fi eld appear the instant the device is bidirectional. Both devices contain a transmitter and a receiver waves typically ranging in frequency from 30 z to 30 z. Such current starts or does it take time to travel and so can ‘talk’ to one another. The communication is complex and the broadcasts require high power transmitters. Most of the RTE radio data rate is very high (e.g. 600 Mbps). Each device can detect errors In the 1850s James Clerk Maxwell began to consider such questions. transmittersWhat operate is atradiation? 200,000 watts (i.e. 200 k) while the power of Main kinds of ionising λ (m) E (eV) inMain the received sources packets of ofionising data and ‘request’radiation that be sent again. At the some local radio transmitters may be as low as 10 watts. He produced a very comprehensive theory of electromagnetic waves same time the router may be communicating with several other local and calculatedradiation that they should travel at a speed of approximately1 pm 1.24 GeV The pie-chart below shows the average contribution from different sources A candle radiates light and heat in all directions and can devicesof ionising and radiation with remote to the averagecomputers Irish via person. the worldwide makes web. the biggest In Ireland (as in most countries) a person must obtain a licence for radio 300,000,000The diagram metres shows per the second. This led him to propose that light was in Radon illuminate a room. From its source the light appears to travel 10 pm 124 MeV contribution and is the cause of about 250 lung cancer cases each year in Comeg is the statutory body responsible for the regulation transmission. The type of licence depends on the application (mobile wavelength and energy of Wireless routers use 2.4 GHz and 5 GHz bands (2400 MHz 5000 in straight lines, called rays, and if something blocks the path fact an electromagnetic wave. Ireland. Radon is a radioactive gas that typically seeps into houses from the of the electronic communications sector (telecommunications, phone, amateur radio, air traffi c services etc.). The licence specifi es the electromagnetic waves on a 100 pm 12.4 MeV MHz). As the word ‘band’ implies, each of these is not single frequency a shadow is formed. Light is a form of radiation. scale; photons on ground. It is a product of the radioactive decay of naturally occurring radiocommunications and broadcasting transmission) and maximum power and the frequency ranges or ‘bands’. Maxwell’slogarithmic theory (1867) described the propagation rays Gamma of electromagnetic1 pm 1.24 MeV but a range of frequencies that is divided into several ‘ ’. uranium or thorium. Since 1998, all new buildings in high channelsradon areas must the postal sector. Its remit covers all kinds of transmission wavesthe — next including step up radio have waves.ten times Twenty years later Heinrich Hertz fi rst A dual-band router can use both of these bands. The diagram shows However,When no licence sunlight is isrequired dispersed for bycertain a prism transmissions a spectrum isthat formed we take as Newton more energy and may cause ten 10 pm 124 keV have a radon barrier installed and, in other areas, a standby radon sump networks including: demonstrated the propagation of radio waves. how— a thetype 2.4 of fanGHz that band draws is airdivided from underinto 14 the channels, floor and manyvents it of to which the outside. for grantedfound today. in 1665. For instance, In 1800 Thomas a mobile Young phone showed must that be lightable was to transmitsome kind of times more ionisations. Note that 100 pm 12.4 keV The EPA’s Office of Radiological Protection (ORP) is overlap;Both methods each canband be is used 22 MHzto reduce wide. radon A router entering can the send building. large amounts • Traditional telephone wire wave and he measured the wavelength of light of different colours; they the term ‘gamma ray’ refers to X-rays responsible for ensuring that people and the radio signals as well as receive them. Mobile phones operate in specifi c • Television and radio frequencies range from about 750 nm (red) to about 400 nm (violet). Typeselectromagnetic of electromagnetic radiation coming waves 1 nm 1.24 keV of data very quickly by using several channels at the same time. radio frequency bands and their power is less than 0.4 W. radiation Ionising environment in Ireland are protected from the harmful It is very easy to reduce the radiation dose from radon by reducing the levels of • Radiocommunications including fi xed wireless Also in 1800 Herschel discovered, using a thermometer, that the spectrum A conductorfrom atomic carrying nuclei; a theycurrent are alternating 10 nm 124 eV radon in the home. There is little that we can do to reduce our exposure to other effects of ionising radiation.

A smart phone may also have ii capability, that is, it uses a specifi ed otherwise identical with high UV • Mobile operators providing voice and data services contained some heat radiation in the dark area beyond the red; we now callone million times per second (i.e. at 100 nm 12.4 eV sources of ionising radiation such as gamma rays, cosmic rays and radiation communicationsthis infra-red protocol radiation and (IR).transmits The following radio signals year (1801) at low Ritter power showed that one megahertzenergy X-rays. or 1 MHz) radiates from the buildings we inhabit, the food we eat and indeed from our own bodies. The ORP• isSatellite a successor services to the Radiological Protection (generally less than 0.1 W). WiFi therefore has a short range ― typically 1 µm 1.24 eV Institute of Ireland which merged with the EPA in 2014. there was some form of radiation beyond the violet end of the spectrum electromagneticThe kinetic energywaves whoseof alpha wave Visible less than which100 metres. could cause chemical change faster than any of the visible colours. lengthparticles is 300 metres.is generally At abetween frequency of 10 µm f (Hz) Measurement of ionising radiation ComReg enables competition in the communications sector It is called ultra-violet radiation (UV). IR 300 MHz5 and the 7 MeV wavelength while that would of beta be just The first thing to decide is what exactly to measure. by facilitating market entry for networks and services and 100 µm 3 THz Source: Wikipedia List of Wlan Channels What are s? 3 metres.particles The generally higher the ranges frequency, from the Theby keyregulating functions access of the to ORP networks are: so as to ensure that 100 keV to 20 MeV. However the 1 mm 300 GHz Option 1: How radioactive is a piece of material; i.e., how many nuclear Today SRDsWhat or ‘short is ionising range radio radiation? devices are in common use. Below shorter the wavelength. (Their product is consumers, both business and residential, have choice in energy of cosmic rays may be −1 disintegrations occur in it every second. • Educating the public on the risks of ionising are some examples, together with their allocated frequencies: 300,000,000, i.e. the speed of light in m s .) 10 mm 30 GHz Bluetooth is a lower power, bidirectional wireless communication system We now know that visible light, IR and UV form a small part of a much thousands of times greater but Unit: becquerel (Bq); 1 Bq = 1 disintegration per second the radiationservices which they wish to use. In a rapidly evolving wider spectrum of electromagnetic waves. Those with shorter wavelengths is commonly about 300 MeV. 100 mm 3 GHz that also uses the 2400 MHz band but divides it into 79 channels, each of The table shows the part of the Non-ionising radiation This does not indicate how much radiation a person might sector, both in technological and commercial terms, ComReg • wireless local area networks (As) including Wi-Fi Microwaves which is just 1 MHz wide or 40 channels that are 2 MHz wide. Bluetooth • Contributing to Government policy on radiation transmit more energy and often interact with matter as particles called electromagnetic spectrum used by SRDs. 1 m 300 MHz absorb; gamma rays would be much less likely to be absorbed provides the framework for the introduction of new services 5 bands in range: 2.4 − 5.9 GHz divides the data to be transmitted into packets that are sent on different protection matters photons. than alpha or beta particles. such as next generation mobile to support smartphones • Bluetooth devices 2.4 − 2.4835 GHz Non-ionising 10 m 30 MHz channels. The receiving device reassembles the data in the correct order. Option 2: Measure the amount energy absorbed per kilogram due to Electromagnetic radiation whose wavelength is less than about 300 nm adio The maximum transmission speed is 50 Mbps and the range is typically • andLicensing similar applications. and regulating the possession and use • car isdoor called openers, ionising automatic radiation because gates it can knock electrons off433 some MHz atoms radiation 100 m 3 MHz radiation; this is the ‘absorbed dose’. of ionising radiation in medicine, industry, research How can electromagnetic waves carry about 10 metres. Bluetooth applications include: −1 • babyand alarms molecules causing ions to form, or to be more precise, ion2.4 pairs. GHz Ionising The boundary between ionising 1 km 300 kHz Unit: gray (Gy): 1 gray = 1 joule per kilogram (1 J kg ) Encouragingand education innovation is also a key role for ComReg. This radiation can damage bio-molecules such as DNA, causing cells to die information For example, an M radio • wireless microphones 5 bands in range: 470 MHz − 1800 MHz and non-ionising radiation is not • smart watches, headphones, earbuds, home audio systems or malfunction. station (e.g. RTE Radio 1 on 88.5 MHz) 10 km 30 kHz Option 3: A calculated measure of the potential damage to body tissues • coversMaintaining both regulatory a national innovations, laboratory forsuch the as implementation universally agreed but is often Radio waves • hands-free mobile phone answering (in car) • R tags (Radio Frequency Identifi cation) 13.56 MHz transmitstaken a to RF be signal100 nm centred, (i.e. with in this due to radiation. of marketmeasurement reviews of under radioactivity the new levels European in the regulatory case, on 88.5 MHz. Its frequency • printing from mobile devices (phone, tablet etc.) • Near-fiIonising eld communication particles (C) 13.56 MHz photon energy of about 12 eV). Unit: sievert (Sv): 1 sievert = 5.5% risk of developing cancer as a result framework,environment and technical innovations. On the radio spectrum is variedRadiation or ‘modulated whose wavelength’ continuously is greater to matchthan that the is variationclassed as in non-ionising the • transferof ofradiation images exposure. from digital Repeated cameras. doses of 1 Sv over minutes or side the role involves development of strategies for • Where appropriate, to provide, or oversee the These devicesIn the 1890suse low certain power materials R (radio were frequency) found to emit in specifia form edof highly RF ionising audioand signal includes that itUV-C ‘carries’., UV-B An, UV-A FM ,radio visible (receiver) light, infrared, detects microwaves, the ‘carrier radio’ hours would be likely to lead to death within a few weeks. management and use of the radio spectrum, new initiatives in radiation which, unlike light, was strongly affected by a magnet and so was (i.e. thewaves RF andsignal) very and low generatesfrequency radio an audio waves signal from power from thelines variation (50 Hz). in The future and the Internet of Things’ provision of, specialist radiation protection services bands. They are not likely to cause harmful interference to other networks The sievert represents the biological effect of an absorbed dose. It is derived the wireless licensing area, and the promotion of Ireland as a different from electromagnetic waves. Some materials emitted positively such as personal dosimetry, radioactivity or to essential public services and so no licence is required for their use. its frequency.The fact that The they communication may not cause is ionisation in one direction does not only. mean that these Thefrom rapidly the gray expanding but employs use a weightingof SRDs thatenables varies many with the domestic type of radiation:and charged particles called alpha particles. Others emitted negatively charged testmeasurement, bed for innovative instrument uses ofcalibration, the spectrum radon (See Test Trial radiations are always harmless. In large doses they can cause body commercial devices to communicate with one another. This ‘nternet of particles, or beta particles. Some materials also emitted high energy 1 Gy of gamma rays, X-rays or beta particles = 1 Sv Irelandmeasurements at www.testandtrial.ie). and product certification What are electromagnetic waves? stissues to heat up faster that blood flow can dissipate the heat. Sunbathing things’ (IoT) with embedded communications technology brings with it electromagnetic waves called gamma rays. All these materials are said can cause sunburn. Even with sunscreens the skin is damaged; the 1 Gy of alpha particles = 20 Sv We take lightto be for radioactive granted. .At the fl ick of a switch we can turn on an A wireless car door key’ contains an RF transmitter; when activated it the possibility of so-called smart homes, intelligent transportation and • Assisting in the development of national plans tanning process is the body’s reaction to DNA damage in skin cells. 1 Gy of protons = 2 Sv ComReg’s expertise in the wireless sector is widely electric lamp. The shape of shadows lead us to think that something is transmits a signal that carries a unique digital code. A receiver in the car smart cities. Appropriate standards and operating protocols are being to deal with nuclear accidents and incidents In 1912 Victor Hess found — ascending above 5000 metres by balloon — that Exposure to UV-A can lead to skin cancer. recognised. In the recent past ComReg has chaired the high coming from the lamp and it seems to travel in straight lines. We can pick up and decodes the signal and if the code is correct it responds by developedThe average to radiation help support dose receivedthe various by people IoT uses in Ireland mentioned each year above. is about It is extremely ionising radiation increased with altitude and that it did not come four millisieverts; 0.004 Sv = 4 mSv = 4000 µSv (microsieverts). However, • levelConducting advisory group and promoting to the European research Commission, on a range the Radio refl ect light with a mirror and refract it with a lens. locking or unlocking the doors. This communication is in one direction. estimated that by 2020 there will be around 50 billion connected devices from the Sun. This cosmic radiation comes from outside our solar system some people receive ten times that dose due to high radon levels in their Spectrumof areas Policy relevant Group, to radiation as well protectionas the Body of European and at least some of it is extra-galactic It is by far the most strongly ionising In 1678 Christiaan Huygens explained the properties of light in terms of FIs, on the other hand, use bidirectional communication. RFID tags 1homes. The greater the dose, the greater the risk. Regulators for Electronic Communications. In addition, for the radiation known. About 90% of it consists of protons, often travelling at over According to ComReg in its key quarterly report for Q2 2016 there were 1,330,946 fi xed • Driving forward programmes of radon waves of some sort. In 1690 Isaac Newton tried to explain the properties do not have batteries and are powered by the RF signal that is sent from broadbandA radon test subscriptions kit can be (an obtained increase from of 0.7% the EPA,from Q1 Office 2016 andof Radiological an increase of 3.9% second year in a row, ComReg was awarded the Business 99% of the speed of light. It also contains alpha particles and lesser amounts measurement and remediation in homes, of light in terms of little particles or ‘corpuscles’ as he called them. the tag reader. The tag responds by sending the required information comparedProtection. to Q2It contains 2015). Most sealed such plastic subscriptions film which rely on is theleft usein placeof wireless for 30 routers. days of heavier nuclei, neutrons and positrons. in Excellenceworkplaces for and Research schools and Development for its Test However, around 1804 Thomas Young demonstrated diffraction and which is picked up and decoded by the reader. In contrast to barcodes, and then returned to EPA. When the film is developed the level of radiation is The speed of a wave is equal to the and Trial Ireland service. That award honours the valuable interference of light — properties that are characteristicf = c/λ of waves. The RFIDs do not require line of sight. For example, a hand held RFID reader indicated by the number of tracks left on it by ionising radiation. • Representing Ireland on international bodies frequency (f) multiplied by the wavelength egulation contribution and difference that ComReg makes to wireless wave theory of light was then universally accepted. But nobody knew what can scan up to fi fty items of clothing on a shelf in one second and record dealing with radiation protection and nuclear (λ). For electromagnetic waves this is E = hf all their details. Some RFID tags contain memory chips and can be In Ireland, the technical criteria for the operation of SRDs on a innovation in Ireland. was actuallywritten waving. as c=f.λ where c is the speed. Common radiation doses and risk matters E = hc/λ joules updated by the tag reader. The following are some applications of RFIDs: licence-exempted basis is set out in ComReg document 0271R9 Find out more about the work of ComReg at www.comreg.ie In 1831 MichaelRearranging Faraday this equationdiscovered we getelectromagnetic f = c/λ. induction, i.e the The accompanying table lists some ‘Thoron’ is a (www.comreg.iemediadlmuploads201512ComReg15131.pdf1 Dental X-ray 5 μSv) • Cooperating with radiation protection authorities E = hc/eλ electron volts • Identifi‘Radon ’cation refers to of goods entering of leaving a premises generationThe of energyelectricity per photonusing a is magnet given by and E = ahf conductor.= Faraday thought traditional name for averageand all SRDsradiation placed doses on commonly the Irish market are required to comply with this. and other relevant organisations overseas. radon 222 (222 Rn). 1 Dublin-London return flight 8 μSv radon 220 (220 Rn). received by people in Ireland. Radon that light mighthc/λ, where have Eelectrical is the energy or magnetic in joules ,properties f is and after years of • PersonalIt is a decay identity product tags with access control It is a decay isIn clearly Europe, the themost radio significant spectrum requirements for SRDs are being trial and errorthe frequency he was eventuallyin hertz and successful. h is Plank’s He published his fi ndings the of uranium 238 (238 1 Chest X-ray 20 μSv For further infromation visit: www.epa.ie/radiation −34 • Monitoring of runners at specifi ed points in a race product of thorium Find this and other lessons on www.sta.ie constant (6.6 × 10 J s). A useful alternative unit of energy for photons is U) with a half life of contributorconsidered to ourby anoverall expert radiation group of radio frequency managers. The following year (1845). This was a remarkable discovery. Indeed, many 232 (232Th) and has Annual cosmic ray dose 350 μSv the . It is found by dividing the energy in joules by the charge • Laundering3.8 days. of work clothing (and recording number washes) exposuregroup will but assist fortunately and advise it is the onone the future radio spectrum needs of IoT. people todayelectron would not volt expect light to be affected by a magnet. a half life of 55.6 Find this and other lessons on www.sta.ie −19 (There are over 30 that we can most easily avoid. on an electron, e (1.602 × 10 C). seconds. Annual radon dose (avg.) 2230 μSv isotopes of radon.) 6. 6. OnOn 16 16August, August, 1960, 1960, Joseph Joseph Kittinger Kittinger esta establishedblished a recorda record for for the the highest highest altitudealtitude parachute parachute jump. jump. Th isTh recordis record remains remains unbroken. unbroken. KittingerKittinger jumped jumped from from a height a height of of31 31km. km. He He fell fell for for 13 13seconds seconds and and then then horthort ange ange adio adiohishis 1.8-metre 1.8-metre canopy canopy parachute parachute opened. opened. This This stabilised stabilised his his fall. fall. Only Only four four minutesminutes and and 36 36seconds seconds more more were were needed needed to tobring bring him him down down to to5 km,5 km, wherewhere his his 8.5-metre 8.5-metre parachute parachute opened, opened, allowing allowing him him to tofall fall at atconstant constant velocity,velocity, until until he hereached reached the the surface surface of theof the earth. earth. eviceevice Communications Communications(Adapted(Adapted from from http://www.centennialofflight.gov http://www.centennialofflight.gov) ) AutomaticAutomatic camera camera recording recording of Kittingerof Kittinger as he as jumped.he jumped. Short Range Radio Device Communications (i) (i) Calculate Calculate the the acceleration acceleration due due to gravityto gravity at aat height a height of 31of 31km km above above the the surface surface of theof the earth. earth. (12)(12) (ii)(ii) What What was was the the downward downward force force exerted exerted on onKittinger Kittinger and and his his equipment equipment at 31at 31km, km, takingtaking their their total total mass mass to beto be180 180 kg? kg? (6)(6)

(iii)(iii) Estimate Estimate how how far farhe hefell fell during during the the first first 13 13seconds. seconds. WhatWhat assumptions assumptions did did you you take take in thisin this calculation? calculation? (12)(12)

(iv)(iv) What What was was his his average average speed speed during during the the next next 4 minutes 4 minutes and and 36 36seconds? seconds? (9)(9)

(v)(v) Assuming Assuming that that the the atmospheric atmospheric pressure pressure remains remains constant, constant, how how much much was was the the force force on ona a tudenttudent Activities Activities aminationaminationhemisphericalhemispherical parachute parachute uestions uestions of diameterof diameter 8.5 8.5 m greatm greater thaner than that that on ona similar a similar parachute parachute of of idid ou ou now? now? yllabusyllabus eferences eferences diameterdiameter 1.8 1.8 m? m? (9)(9)

TheThe main main syllabus syllabus references references for for the the lesson lesson are: are: 1.1. UsingUsing a amicrowave microwave oven oven and and an an egg egg it itis ispossible possible to to estimate estimate (vi)(vi) Calculate Calculate the the upthrust upthrust that that acted acted on onKittinger Kittinger wh when enhe hereached reached constant constant velocity velocity in thein the last last FreuencyFreuency Hopping Hopping LeavingLeavingstage stageCertifi ofCertifi hisof his descent descentcate cate (assume (assume Physics Physics g = g 9.81 = 9.81 m sm(HL)–2 sduring(HL)–2 during 2015,this 2015,this stage). stage). Q. Q. 6 6 (8)(8) thethe wavelength wavelength of of microwaves microwaves as as follows. follows. LeavingLeaving Certifi Certifi cate cate Physics Physics (pp. (pp. 30-33) 30-33) 6 6 24 24 • • AsAs the the name name implies, implies, frequency frequency hopping hopping is isa aradio radio technology technology in in a)a) The(radiusThe(radius diagram of diagram earthof earth =6.36 =6.36 shows ×shows 10 × 10m; m;massa massasimplifi ofsimplifi earthof earth = ed 5.97 = ed 5.97 version × version10 × 10 kg) kg) of of the the electromagnetic electromagnetic • •Remove Remove the the turntable turntable device. device. whichwhich the the transmitter transmitter does does not not use use a asingle single frequency frequency but but ‘hops’ ‘hops’ • • WaveWave phenomena: phenomena: refl refl ection, ection, refraction, refraction, diffraction, diffraction, interference, interference, spectrum. spectrum. Name Name the the sections sections labelled labelled A Aand and B Bin in the the diagram. diagram. • •Crack Crack the the egg egg and and separate separate and and retain retain the the egg egg white. white. This This betweenbetween many many different different frequencies frequencies in in a aparticular particular range. range. This This polarisation.polarisation. 7. 7. shouldshould be be gently gently mixed mixed (not (not whisked) whisked) to to make make it itas as uniform uniform makesmakes it itdiffi diffi cult cult for for someone someone using using a aradio radio receiver receiver to to ‘listen ‘listen in’ in’ • • DiffractionDiffraction effects: effects: at at an an obstacle obstacle and and at at a aslit slit with with reference reference to to asas possible. possible. A A B B unlessunless they they know know the the sequence sequence of of frequencies frequencies in in advance. advance. rays rays TV TV light light

signifisignifi cance cance of of the the wavelength. wavelength. radar radar γ γ radio radio X-rays X-rays X-rays FM radio FM radio

AM radio AM radio • • ThereThere are are a afew few different different implementations implementations of of frequency frequency hopping hopping short wave short wave • •Spread Spread the the egg egg white white evenly evenly on on the the glass glass microwave microwave oven oven microwaves microwaves • • EverydayEveryday examples, examples, e.g. e.g. radio radio waves, waves, waves waves at at sea, sea, seismic seismic plateplate and and place place it itin in the the microwave microwave oven. oven. Cook Cook it itat at full full power power inin common common use use today. today. In In the the case case of of FHSS FHSS (Frequency (Frequency waves.waves. 10510 5 10610 6 10710 7 10810 8 10910 9 101010 1010 11101110121012101310131014101410151015101610 1610 1710 1710 1810 18Hz Hz forfor about about 30 30 seconds. seconds. Stop Stop the the cooking cooking as as soon soon as as you you see see HoppingHopping Spread Spread Spectrum) Spectrum) the the frequency frequency switches switches between between • • LongitudinalLongitudinal and and transverse transverse waves: waves: frequency, frequency, amplitude, amplitude, cookedcooked patches patches appearing. appearing. b)b) DescribeTheDescribeThe diagram diagram shows how shows how a simplifiedto a simplifiedto detect detect versi versi eachon eachonof theof theof electromagnetic of electromagneticthese these radiations. radiations.spectrum. spectrum. 7979 frequencies frequencies (or (or ‘channels’) ‘channels’) in in a aseemingly seemingly random random manner manner wavelength,wavelength, velocity. velocity. Relationship Relationship c c= =f λ.f λ. NameName the the sections sections labelled labelled A andA and B inB thein the diagram. diagram. hundredshundreds of of times times every every second. second. Early Early versions versions of of Bluetooth Bluetooth • •Measure Measure the the distance distance between between the the centres centres of of adjacent adjacent pairs pairs c)c) AnDescribeAnDescribe electromagnetic electromagnetic how how to detectto detect each each of radiationtheseof radiationthese radiations. radiations. has has a awavelength wavelength of of 4 4m. m. Name Name(15) (15)the the • • TheThe electromagnetic electromagnetic spectrum: spectrum: Relative Relative positions positions of of radiations radiations in in usedused this this technique. technique. ofof cooked cooked spots. spots. This This would would be be expected expected to to be be about about 6 6cm. cm. sectionAnsectionAn electromagnetic electromagnetic of of the the radiation electromagnetic radiation electromagnetic ha sha a swavelength a wavelength of spectrum 4of spectrumm. 4 m. in in which which this this radiation radiation is is termsterms of of wavelength wavelength and and frequency. frequency. located.Namelocated.Name the the section section of theof the electr electromagneticomagnetic spectrum spectrum in whichin which this this radiation radiation is located.is located. (9)(9) • • SinceSince 2003 2003 Bluetooth Bluetooth devices devices use use AFH AFH (Adaptive (Adaptive Frequency Frequency • •The The cooked cooked spots spots indicate indicate the the positions positions of of the the antinodes antinodes of of Hopping).Hopping). For For example, example, in in a aroom room in in which which a awireless wireless local local area area ciencecience and and echnology echnology in in Action Action is isalso also widely widely used used by by d)d) DistinguishDistinguishDistinguishDistinguish between between between betweeninte interferencerference interference and interference and diffraction. diffraction. and and diffraction. diffraction. Can Can a adiffraction diffraction thethe microwaves; microwaves; this this is ishalf half the the wavelength. wavelength. CanCan a diffraction a diffraction grating grating which which diffracts diffracts light light also also diffr diffractact X-rays? X-rays? Justify Justify your your answer. answer. (21) (21) networknetwork (WLAN) (WLAN) is isin in use use a aBluetooth Bluetooth device device adapts adapts by by avoiding avoiding TransitionTransition ear ear classes. classes. grating grating which which diffracts diffracts light light also also diffract diffract X-rays? X-rays? Justify Justify your your answer. answer. • •Use Use the the relationship relationship c c= =f λf λto to calculate calculate the the frequency. frequency. LightLight travels travels as aas transverse a transverse wave. wave. Name Name another another type type of waveof wave motion motion and and give give frequenciesfrequencies that that clash clash with with those those used used by by the the WLAN WLAN router. router. e)e) LighttwoLighttwo differences differencestravels travels between betweenas as athese atransversethese transversetw otw typeso types of waveof wave. wave wave. motion. motion. Name Name another another type type of of wave wave(11)(11) (This(This is istypically typically 2,450 2,450 MHz.) MHz.) motionmotion and and give give two two differences differencespagepage 6 ofbetween 6 12 ofbetween 12 these these two two types types of of wave wave LearningLearning Outcomes Outcomes 2.2. InvestigateInvestigate possible possible medical medical applications applications of of SRDs SRDs such such as: as: motion.motion. iographicaliographical Notes Notes • •wireless wireless monitoring monitoring of of patient patient vital vital signs signs in in hospital hospital OnOn completion completion of of this this lesson, lesson, students students should should be be able able to: to: LeavingLeaving Certifi Certifi cate cate Physics Physics (OL) (OL) 2009, 2009, Q. Q. 5 5d d CharlesCharles Walton Walton (121 (121 211) 211) • •home home monitoring monitoring of of people people with with chronic chronic diseases diseases • • outlineoutline the the key key discoveries discoveries that that led led to to the the development development of of CalculateCalculate the the wavelength wavelength of of a aradio radio wave wave whose whose frequency frequency is is252 252 kHz. kHz. 8 8 −1 −1 CharlesCharles Walton Walton grew grew up up in in Maryland Maryland and and New New York York State. State. wirelesswireless communication communication • •programmable programmable implants implants (e.g. (e.g. pacemaker). pacemaker). ( c( c= =f λf ,λ c, c= =3.0 3.0 × ×10 10 m m s s ) ) HeHe graduated graduated in in 1943 1943 with with a adegree degree in in Electrical Electrical engineering, engineering, • • outlineoutline how how radio radio waves waves are are propagated propagated 3.3. InvestigateInvestigate current current applications applications of of RFIDs, RFIDs, including: including: andand later later received received a amaster’s master’s degree. degree. Initially Initially he he worked worked with with LeavingLeaving Certifi Certifi cate cate Physics Physics (OL) (OL) 2003, 2003, Q. Q. 12 12 b b thethe US US Army Army Signal Signal Corps Corps and and later later with with at at IBM’s IBM’s research research and and • • calculatecalculate wavelengths wavelengths and and frequencies frequencies • •event event ticketing ticketing TheThe diagram diagram shows shows a asimple simple form form of of the the electromagnetic electromagnetic spectrum, spectrum, developmentdevelopment laboratories laboratories until until 1970. 1970. He He then then set set up up his his own own • • explainexplain what what is ismeant meant by by ‘SRD’ ‘SRD’ • •tracking tracking goods goods withwith wavelength wavelength increasing increasing from from left left to to right. right. companycompany (Proximity (Proximity Devices) Devices) to to manufacture manufacture devices devices based based on on • • describedescribe some some common common SRD SRD applications applications hishis patents. patents. • •security security (anti (anti theft). theft). • • distinguishdistinguish between between broadcast broadcast radio radio and and SRD SRD shortshort wavelength wavelength longlong wavelength wavelength AlthoughAlthough he he registered registered more more than than 50 50 patents patents his his fame fame rests rests on on 4.4. WhatWhat future future uses uses can can you you envisage envisage for for RFIDs RFIDs • • givegive examples examples of of unidirectional unidirectional and and bidirectional bidirectional SRDs. SRDs. gammagamma rays rays lightlight radioradio waves waves oneone in in particular particular 1973 1973 patent patent -- --a a‘portable ‘portable radio radio frequency frequency emitting emitting identifiidentifi er’. er’. Many Many of of his his inventions inventions took took a along long time time to to catch catch on on and and in in CopyCopy this this diagram diagram and and indicate indicate on on it itthe the positions positions of of the the following: following: somesome cases cases the the patent patent had had already already expired. expired. As As a aresult result he he did did not not microwaves;microwaves; infrared; infrared; ultraviolet; ultraviolet; X-rays. X-rays. GeneralGeneral Learning Learning Points Points profiprofi t fromt from some some of of his his inventions. inventions. True/FalseTrue/False uestions uestions CharlesCharles Walton Walton is isbest best known known as as the the fi rstfi rst patent patent holder holder for for the the RFID RFID LeavingLeaving Certifi Certifi cate cate Physics Physics (HL) (HL) 2015, 2015, Q. Q. 6 6 TheseThese are are additional additional relevant relevant points points which which are are (radio(radio frequency frequency identifi identifi cation) cation) device. device. Although Although others others contributed contributed usedused to to extend extend knowledge knowledge and and facilitate facilitate discussion. discussion. a)a) TVTV signals signals are are in infact fact radio radio waves. waves. T T F F A AGlobal Global Positioning Positioning Systems Systems (GPS) (GPS) receiver receiver can can calculate calculate its its position position toto the the invention invention Walton Walton was was awarded awarded ten ten patents patents in in all all for for various various onon Earth Earth to to within within a afew few metres. metres. It Itpicks picks up up radio-wave radio-wave signals signals from from • • RadioRadio waves waves form form the the long long wavelength wavelength part part of of the the b)b) TheThe frequency frequency of of radio radio waves waves ranges ranges from from 30 30 Hz Hz to to 30 30 MHz MHz T T F F RFID-relatedRFID-related devices. devices. His His 1973 1973 design design for for a aPortable Portable radio radio severalseveral of of the the 32 32 GPS GPS satellites satellites orbiting orbiting the the Earth. Earth. GPS GPS satellites satellites orbit orbit frequencyfrequency emitting emitting identifi identifi er” er” was was awarded awarded a apatent patent in in 1983; 1983; it itwas was electromagneticelectromagnetic spectrum. spectrum. The The shortest shortest wavelength wavelength radio radio waves waves c)c) A Alicence licence is isrequired required to to broadcast broadcast radio radio signals. signals. T T F F thethe Earth Earth in in Medium Medium Earth Earth Orbit Orbit (MEO) (MEO) with with a aperiod period of of 12 12 hours. hours. thethe fi rstfi rst device device to to be be specifi specifi cally cally called called an an RFID. RFID. areare called called microwaves microwaves (1 (1 mm mm to to 1 1m). m). d)d) SRDsSRDs signals signals are are confi confi ned ned to to specifi specifi ed ed radio radio bands. bands. T T F F CalculateCalculate • • LightLight is isalso also electromagnetic electromagnetic but but has has much much shorter shorter wavelength wavelength e)e) TheThe power power of of SRDs SRDs is isabout about 10 10 watts. watts. T T F F thanthan radio radio waves waves (1 (1 ×10 ×10−6 −6m). m). f) f) WiFiWiFi is isa aparticular particular SRD SRD application. application. T T F F (i)(i) the the height height of of a aGPS GPS satellite satellite above above the the Earth’s Earth’s surface surface • • ElectromagneticElectromagnetic waves waves travel travel at at the the speed speed of of light. light. (3 (3 ×10 ×108 m8 m s −1s)−1) eviseevise The The Terms Terms g)g) CreditCredit card card transactions transactions can can be be carried carried out out using using Near-fi Near-fi eld eld (ii)(ii) the the speed speed of of a aGPS GPS satellite satellite • • ShortShort range range devices devices (SRDs) (SRDs) are are digital digital communication communication devices devices communicationcommunication (NFC). (NFC). T T F F (iii)(iii) the the minimum minimum time time it ittakes takes a aGPS GPS signal signal to to travel travel from from the the satellite satellite CanCan you you recall recall the the meaning meaning of of the the following following terms terms thatthat operate operate at at low low power power ( ( 1 1W). W). No No licence licence is isrequired required for for their their h)h) IsaacIsaac Newton Newton discovered discovered radio radio waves waves in in1690. 1690. T T F F toto a areceiver receiver on on the the surface surface of of the the Earth. Earth. RevisingRevising terminology terminology is isa apowerful powerful aid aid to to recall recall and and retention. retention. normalnormal use. use. ExplainExplain why why GPS GPS satellites satellites are are not not classed classed as as geostationary geostationary satellites. satellites. i) i) LightLight waves waves are are electromagnetic. electromagnetic. T T F F alternatingalternating current, current, bands, bands, barcodes, barcodes, Bluetooth, Bluetooth, broadcasts, broadcasts, carrier, carrier, • • CommonCommon SRDs SRDs applications applications include include Bluetooth, Bluetooth, RFID RFID tags tags (Radio (Radio channels,channels, diffraction, diffraction, digital digital code, code, electromagnetic electromagnetic induction, induction, FrequencyFrequency Identifi Identifi cation), cation), Near-fi Near-fi eld eld communication communication (NFC) (NFC) and and j) j) RFIDsRFIDs can can transmit transmit radio radio signals. signals. T T F F Radio-waves,Radio-waves, such such as as those those used used by by GPS GPS satellites, satellites, have have the the electromagneticelectromagnetic spectrum, spectrum, electromagnetic electromagnetic waves, waves, FM, FM, GHz, GHz, Hz, Hz, wirelesswireless local local area area networks networks (WLANs). (WLANs). k)k) AnAn alternating alternating current current produces produces an an alternating alternating magnetic magnetic fi eld. fi eld. T T F F lowestlowest frequency frequency of of all all electromagnetic electromagnetic radiation radiation types. types. What What type type of of electromagneticelectromagnetic radiation radiation has has the the next next lowest lowest frequency frequency interference,interference, Internet Internet of of Things, Things, kW, kW, magnetic magnetic fi eld, fi eld, Mbps, Mbps, modulated, modulated, • • It Itis isestimated estimated that that by by 2020 2020 there there will will be be around around 50 50 billion billion l) l) BluetoothBluetooth devices devices transmit transmit on on one one radio radio frequency frequency band. band. T T F F (mass(mass of of Earth Earth = =5.97 5.97 × ×10 1024 24kg; kg; radius radius of of Earth Earth = =6371 6371 km) km) NFC,NFC, packets, packets, power, power, protocol, protocol, radio radio waves, waves, refract, refract, RFID, RFID, short short range, range, connectedconnected devices devices ― ― that that is ismany many times times more more than than the the global global SRD,SRD, watt, watt, WiFi, WiFi, wireless wireless routers, routers, WLAN. WLAN. CheckCheck your your answers answers to to these these uestions uestions on on www.sta.ie. www.sta.ie. population.population. CheckCheck the the lossary lossary of of terms terms for for this this lesson lesson on on www.sta.ie www.sta.ie 6. 6. OnOn 16 16August, August, 1960, 1960, Joseph Joseph Kittinger Kittinger esta establishedblished a record a record for forthe the highest highest altitudealtitude parachute parachute jump. jump. Th isTh recordis record remains remains unbroken. unbroken. KittingerKittinger jumped jumped from from a height a height of 31of 31km. km. He Hefell fell for for13 13seconds seconds and and then then horthort ange ange adio adiohis his1.8-metre 1.8-metre canopy canopy parachute parachute opened. opened. This This stabilised stabilised his hisfall. fall. Only Only four four minutesminutes and and 36 36seconds seconds more more were were needed needed to bringto bring him him down down to 5to km,5 km, wherewhere his his8.5-metre 8.5-metre parachute parachute opened, opened, allowing allowing him him to tofall fall at atconstant constant velocity,velocity, until until he reachedhe reached the the surface surface of theof the earth. earth. eviceevice Communications Communications(Adapted(Adapted from from http://www.centennialofflight.gov http://www.centennialofflight.gov) ) AutomaticAutomatic camera camera recording recording of Kittingerof Kittinger as he as jumped. he jumped. Short Range Radio Device Communications (i) (i) Calculate Calculate the theacceleration acceleration due due to gravityto gravity at aat height a height of 31of 31km km above above the the surface surface of theof the earth. earth. (12)(12) (ii)(ii) What What was was the the downward downward force force exerted exerted on onKittinger Kittinger and and his hisequipment equipment at 31at 31km, km, takingtaking their their total total mass mass to beto 180be 180 kg? kg? (6) (6)

(iii)(iii) Estimate Estimate how how far farhe fellhe fell during during the the first first 13 13seconds. seconds. WhatWhat assumptions assumptions did did you you take take in thisin this calculation? calculation? (12)(12)

(iv)(iv) What What was was his hisaverage average speed speed during during the the next next 4 minutes 4 minutes and and 36 36seconds? seconds? (9) (9)

(v) (v) Assuming Assuming that that the the atmospheric atmospheric pressure pressure remains remains constant, constant, how how much much was was the the force force on ona a tudenttudent Activities Activities aminationaminationhemisphericalhemispherical parachute parachute uestions uestions of diameterof diameter 8.5 8.5 m greatm greater thaner than that that on ona similar a similar parachute parachute of of idid ou ou now? now? yllabusyllabus eferences eferences diameterdiameter 1.8 1.8 m? m? (9) (9)

TheThe main main syllabus syllabus references references for for the the lesson lesson are: are: 1.1. UsingUsing a amicrowave microwave oven oven and and an an egg egg it isit ispossible possible to to estimate estimate (vi)(vi) Calculate Calculate the theupthrust upthrust that that acted acted on onKittinger Kittinger wh enwh heen reachedhe reached constant constant velocity velocity in thein thelast last FreuencyFreuency Hopping Hopping LeavingLeavingstage stageCertifi ofCertifi hisof hisdescent descentcate cate (assume (assume Physics Physics g = g 9.81 = 9.81 m sm(HL)–2 sduring(HL)–2 during 2015,this 2015,this stage). stage). Q. Q. 6 6 (8) (8) thethe wavelength wavelength of of microwaves microwaves as as follows. follows. LeavingLeaving Certifi Certifi cate cate Physics Physics (pp. (pp. 30-33) 30-33) 6 6 24 24 • • AsAs the the name name implies, implies, frequency frequency hopping hopping is isa aradio radio technology technology in in a)a) The (radiusThe(radius diagram of diagram earthof earth =6.36 =6.36 shows × shows 10 × 10m; m;massa massasimplifi of simplifi earthof earth = ed 5.97 = ed 5.97 version × 10version × 10 kg) kg) of of the the electromagnetic electromagnetic • •Remove Remove the the turntable turntable device. device. whichwhich the the transmitter transmitter does does not not use use a asingle single frequency frequency but but ‘hops’ ‘hops’ • • WaveWave phenomena: phenomena: refl refl ection, ection, refraction, refraction, diffraction, diffraction, interference, interference, spectrum. spectrum. Name Name the the sections sections labelled labelled A Aand and B Bin inthe the diagram. diagram. • •Crack Crack the the egg egg and and separate separate and and retain retain the the egg egg white. white. This This betweenbetween many many different different frequencies frequencies in ina aparticular particular range. range. This This polarisation.polarisation. 7. 7. shouldshould be be gently gently mixed mixed (not (not whisked) whisked) to to make make it asit as uniform uniform makesmakes it diffiit diffi cult cult for for someone someone using using a aradio radio receiver receiver to to ‘listen ‘listen in’ in’ • • DiffractionDiffraction effects: effects: at at an an obstacle obstacle and and at at a aslit slit with with reference reference to to asas possible. possible. A A B B unlessunless they they know know the the sequence sequence of of frequencies frequencies in inadvance. advance. rays rays TV TV light light

signifisignifi cance cance of of the the wavelength. wavelength. radar radar γ γ radio radio X-rays X-rays X-rays X-rays FM radio FM radio

AM radio AM radio • • ThereThere are are a afew few different different implementations implementations of of frequency frequency hopping hopping short wave short wave • •Spread Spread the the egg egg white white evenly evenly on on the the glass glass microwave microwave oven oven microwaves microwaves • • EverydayEveryday examples, examples, e.g. e.g. radio radio waves, waves, waves waves at at sea, sea, seismic seismic plateplate and and place place it init inthe the microwave microwave oven. oven. Cook Cook it atit at full full power power in incommon common use use today. today. In In the the case case of of FHSS FHSS (Frequency (Frequency waves.waves. 10510 5 10610 6 10710 7 10810 8 10910 9 101010 1010 11101110121012101310131014101410151015101610 1610 1710 1710 1810 18Hz Hz forfor about about 30 30 seconds. seconds. Stop Stop the the cooking cooking as as soon soon as as you you see see HoppingHopping Spread Spread Spectrum) Spectrum) the the frequency frequency switches switches between between • • LongitudinalLongitudinal and and transverse transverse waves: waves: frequency, frequency, amplitude, amplitude, cookedcooked patches patches appearing. appearing. b)b) Describe TheDescribeThe diagram diagram shows how shows how a simplifiedto a simplifiedto detect detect versi versi eachon eachonof theof ofthe electromagnetic of electromagneticthese these radiations. radiations.spectrum. spectrum. 7979 frequencies frequencies (or (or ‘channels’) ‘channels’) in ina aseemingly seemingly random random manner manner wavelength,wavelength, velocity. velocity. Relationship Relationship c =c =f λ.f λ. NameName the the sections sections labelled labelled A and A and B in B thein the diagram. diagram. hundredshundreds of of times times every every second. second. Early Early versions versions of of Bluetooth Bluetooth • •Measure Measure the the distance distance between between the the centres centres of of adjacent adjacent pairs pairs c)c) AnDescribeAnDescribe electromagnetic electromagnetic how how to detectto detect each each of radiationtheseof radiationthese radiations. radiations. has has a awavelength wavelength of of 4 4m. m. Name Name(15) (15)the the • • TheThe electromagnetic electromagnetic spectrum: spectrum: Relative Relative positions positions of of radiations radiations in in usedused this this technique. technique. ofof cooked cooked spots. spots. This This would would be be expected expected to to be be about about 6 6cm. cm. sectionAnsectionAn electromagnetic electromagnetic of of the the radiation electromagnetic radiation electromagnetic has ha a swavelength a wavelength of spectrum 4of spectrumm. 4 m. in inwhich which this this radiation radiation is is termsterms of of wavelength wavelength and and frequency. frequency. located.Namelocated.Name the the section section of theof the electr electromagneticomagnetic spectrum spectrum in whichin which this this radiation radiation is located. is located. (9) (9) • • SinceSince 2003 2003 Bluetooth Bluetooth devices devices use use AFH AFH (Adaptive (Adaptive Frequency Frequency • •The The cooked cooked spots spots indicate indicate the the positions positions of of the the antinodes antinodes of of Hopping).Hopping). For For example, example, in ina aroom room in inwhich which a awireless wireless local local area area ciencecience and and echnology echnology in in Action Action is isalso also widely widely used used by by d)d) Distinguish DistinguishDistinguishDistinguish between between between betweeninte interferencerference interference and interference and diffraction. diffraction. and and diffraction. diffraction. Can Can a adiffraction diffraction thethe microwaves; microwaves; this this is ishalf half the the wavelength. wavelength. CanCan a diffraction a diffraction grating grating which which diffracts diffracts light light also also diffr diffract actX-rays? X-rays? Justify Justify your your answer. answer. (21) (21) networknetwork (WLAN) (WLAN) is isin inuse use a aBluetooth Bluetooth device device adapts adapts by by avoiding avoiding TransitionTransition ear ear classes. classes. grating grating which which diffracts diffracts light light also also diffract diffract X-rays? X-rays? Justify Justify your your answer. answer. • •Use Use the the relationship relationship c =c =f λf toλ to calculate calculate the the frequency. frequency. LightLight travels travels as aas transverse a transverse wave. wave. Name Name another another type type of waveof wave motion motion and and give give frequenciesfrequencies that that clash clash with with those those used used by by the the WLAN WLAN router. router. e)e) Light twoLighttwo differences differencestravels travels between betweenas as athese atransversethese transversetw otw typeso types of waveof wave. wave wave. motion. motion. Name Name another another type type of of wave (11)wave(11) (This(This is istypically typically 2,450 2,450 MHz.) MHz.) motionmotion and and give give two two differences differencespagepage 6 ofbetween 612 ofbetween 12 these these two two types types of of wave wave LearningLearning Outcomes Outcomes 2.2. InvestigateInvestigate possible possible medical medical applications applications of of SRDs SRDs such such as: as: motion.motion. iographicaliographical Notes Notes • •wireless wireless monitoring monitoring of of patient patient vital vital signs signs in inhospital hospital OnOn completion completion of of this this lesson, lesson, students students should should be be able able to: to: LeavingLeaving Certifi Certifi cate cate Physics Physics (OL) (OL) 2009, 2009, Q. Q. 5 5d d CharlesCharles Walton Walton (121 (121 211) 211) • •home home monitoring monitoring of of people people with with chronic chronic diseases diseases • • outlineoutline the the key key discoveries discoveries that that led led to to the the development development of of CalculateCalculate the the wavelength wavelength of of a aradio radio wave wave whose whose frequency frequency is is252 252 kHz. kHz. 8 8 −1 −1 CharlesCharles Walton Walton grew grew up up in inMaryland Maryland and and New New York York State. State. wirelesswireless communication communication • •programmable programmable implants implants (e.g. (e.g. pacemaker). pacemaker). ( c( =c =f λf, λc, =c =3.0 3.0 × ×10 10 m m s s ) ) HeHe graduated graduated in in1943 1943 with with a adegree degree in inElectrical Electrical engineering, engineering, • • outlineoutline how how radio radio waves waves are are propagated propagated 3.3. InvestigateInvestigate current current applications applications of of RFIDs, RFIDs, including: including: andand later later received received a amaster’s master’s degree. degree. Initially Initially he he worked worked with with LeavingLeaving Certifi Certifi cate cate Physics Physics (OL) (OL) 2003, 2003, Q. Q. 12 12 b b thethe US US Army Army Signal Signal Corps Corps and and later later with with at at IBM’s IBM’s research research and and • • calculatecalculate wavelengths wavelengths and and frequencies frequencies • •event event ticketing ticketing TheThe diagram diagram shows shows a asimple simple form form of of the the electromagnetic electromagnetic spectrum, spectrum, developmentdevelopment laboratories laboratories until until 1970. 1970. He He then then set set up up his his own own • • explainexplain what what is ismeant meant by by ‘SRD’ ‘SRD’ • •tracking tracking goods goods withwith wavelength wavelength increasing increasing from from left left to to right. right. companycompany (Proximity (Proximity Devices) Devices) to to manufacture manufacture devices devices based based on on • • describedescribe some some common common SRD SRD applications applications hishis patents. patents. • •security security (anti (anti theft). theft). • • distinguishdistinguish between between broadcast broadcast radio radio and and SRD SRD shortshort wavelength wavelength longlong wavelength wavelength AlthoughAlthough he he registered registered more more than than 50 50 patents patents his his fame fame rests rests on on 4.4. WhatWhat future future uses uses can can you you envisage envisage for for RFIDs RFIDs • • givegive examples examples of of unidirectional unidirectional and and bidirectional bidirectional SRDs. SRDs. gammagamma rays rays lightlight radioradio waves waves oneone in inparticular particular 1973 1973 patent patent -- --a a‘portable ‘portable radio radio frequency frequency emitting emitting identifiidentifi er’. er’. Many Many of of his his inventions inventions took took a along long time time to to catch catch on on and and in in CopyCopy this this diagram diagram and and indicate indicate on on it theit the positions positions of of the the following: following: somesome cases cases the the patent patent had had already already expired. expired. As As a aresult result he he did did not not microwaves;microwaves; infrared; infrared; ultraviolet; ultraviolet; X-rays. X-rays. GeneralGeneral Learning Learning Points Points profiprofi t from t from some some of of his his inventions. inventions. True/FalseTrue/False uestions uestions CharlesCharles Walton Walton is isbest best known known as as the the fi rst fi rst patent patent holder holder for for the the RFID RFID LeavingLeaving Certifi Certifi cate cate Physics Physics (HL) (HL) 2015, 2015, Q. Q. 6 6 TheseThese are are additional additional relevant relevant points points which which are are (radio(radio frequency frequency identifi identifi cation) cation) device. device. Although Although others others contributed contributed usedused to to extend extend knowledge knowledge and and facilitate facilitate discussion. discussion. a)a) TVTV signals signals are are in infact fact radio radio waves. waves. T T F F A AGlobal Global Positioning Positioning Systems Systems (GPS) (GPS) receiver receiver can can calculate calculate its its position position toto the the invention invention Walton Walton was was awarded awarded ten ten patents patents in inall all for for various various onon Earth Earth to to within within a afew few metres. metres. It Itpicks picks up up radio-wave radio-wave signals signals from from • • RadioRadio waves waves form form the the long long wavelength wavelength part part of of the the b)b) TheThe frequency frequency of ofradio radio waves waves ranges ranges from from 30 30 Hz Hz to to30 30 MHz MHz T T F F RFID-relatedRFID-related devices. devices. His His 1973 1973 design design for for a aPortable Portable radio radio severalseveral of of the the 32 32 GPS GPS satellites satellites orbiting orbiting the the Earth. Earth. GPS GPS satellites satellites orbit orbit frequencyfrequency emitting emitting identifi identifi er” er” was was awarded awarded a apatent patent in in1983; 1983; it wasit was electromagneticelectromagnetic spectrum. spectrum. The The shortest shortest wavelength wavelength radio radio waves waves c) c) A Alicence licence is isrequired required to tobroadcast broadcast radio radio signals. signals. T T F F thethe Earth Earth in inMedium Medium Earth Earth Orbit Orbit (MEO) (MEO) with with a aperiod period of of 12 12 hours. hours. thethe fi rst fi rst device device to to be be specifi specifi cally cally called called an an RFID. RFID. areare called called microwaves microwaves (1 (1 mm mm to to 1 1m). m). d)d) SRDsSRDs signals signals are are confi confi ned ned to tospecifi specifi ed ed radio radio bands. bands. T T F F CalculateCalculate • • LightLight is isalso also electromagnetic electromagnetic but but has has much much shorter shorter wavelength wavelength e)e) TheThe power power of ofSRDs SRDs is isabout about 10 10 watts. watts. T T F F thanthan radio radio waves waves (1 (1 ×10 ×10−6 −6m). m). f) f) WiFiWiFi is isa particulara particular SRD SRD application. application. T T F F (i)(i) the the height height of of a aGPS GPS satellite satellite above above the the Earth’s Earth’s surface surface • • ElectromagneticElectromagnetic waves waves travel travel at at the the speed speed of of light. light. (3 (3 ×10 ×108 m8 m s−1 s)−1) eviseevise The The Terms Terms g)g) CreditCredit card card transactions transactions can can be be carried carried out out using using Near-fi Near-fi eld eld (ii)(ii) the the speed speed of of a aGPS GPS satellite satellite • • ShortShort range range devices devices (SRDs) (SRDs) are are digital digital communication communication devices devices communicationcommunication (NFC). (NFC). T T F F (iii)(iii) the the minimum minimum time time it takesit takes a aGPS GPS signal signal to to travel travel from from the the satellite satellite CanCan you you recall recall the the meaning meaning of of the the following following terms terms thatthat operate operate at at low low power power ( ( 1 1W). W). No No licence licence is isrequired required for for their their h)h) IsaacIsaac Newton Newton discovered discovered radio radio waves waves in in1690. 1690. T T F F toto a areceiver receiver on on the the surface surface of of the the Earth. Earth. RevisingRevising terminology terminology is isa apowerful powerful aid aid to to recall recall and and retention. retention. normalnormal use. use. ExplainExplain why why GPS GPS satellites satellites are are not not classed classed as as geostationary geostationary satellites. satellites. i) i) LightLight waves waves are are electromagnetic. electromagnetic. T T F F alternatingalternating current, current, bands, bands, barcodes, barcodes, Bluetooth, Bluetooth, broadcasts, broadcasts, carrier, carrier, • • CommonCommon SRDs SRDs applications applications include include Bluetooth, Bluetooth, RFID RFID tags tags (Radio (Radio channels,channels, diffraction, diffraction, digital digital code, code, electromagnetic electromagnetic induction, induction, FrequencyFrequency Identifi Identifi cation), cation), Near-fi Near-fi eld eld communication communication (NFC) (NFC) and and j) j) RFIDsRFIDs can can transmit transmit radio radio signals. signals. T T F F Radio-waves,Radio-waves, such such as as those those used used by by GPS GPS satellites, satellites, have have the the electromagneticelectromagnetic spectrum, spectrum, electromagnetic electromagnetic waves, waves, FM, FM, GHz, GHz, Hz, Hz, wirelesswireless local local area area networks networks (WLANs). (WLANs). k) k) AnAn alternating alternating current current produces produces an an alternating alternating magnetic magnetic fi eld. fi eld. T T F F lowestlowest frequency frequency of of all all electromagnetic electromagnetic radiation radiation types. types. What What type type of of electromagneticelectromagnetic radiation radiation has has the the next next lowest lowest frequency frequency interference,interference, Internet Internet of ofThings, Things, kW, kW, magnetic magnetic fi eld, fi eld, Mbps, Mbps, modulated, modulated, • • It Itis isestimated estimated that that by by 2020 2020 there there will will be be around around 50 50 billion billion l) l) BluetoothBluetooth devices devices transmit transmit on on one one radio radio frequency frequency band. band. T T F F (mass(mass of of Earth Earth = =5.97 5.97 × ×10 1024 kg;24 kg; radius radius of of Earth Earth = =6371 6371 km) km) NFC,NFC, packets, packets, power, power, protocol, protocol, radio radio waves, waves, refract, refract, RFID, RFID, short short range, range, connectedconnected devices devices ― ― that that is ismany many times times more more than than the the global global SRD,SRD, watt, watt, WiFi, WiFi, wireless wireless routers, routers, WLAN. WLAN. CheckCheck your your answers answers to to these these uestions uestions on on www.sta.ie. www.sta.ie. population.population. CheckCheck the the lossary lossary of of terms terms for for this this lesson lesson on on www.sta.ie www.sta.ie