Near Field Communication

Total Page:16

File Type:pdf, Size:1020Kb

Near Field Communication Near field communication A summary of near-field communication An NFC-enabled mobile phone interacting with a SmartPoster A ticket stamping machine of the Austrian Federal Railways that can be used to purchase mobile tickets (“Handy-Ticket”). Near-field (or nearfield) communication (NFC) is a form of short-range wireless communication where the antenna used is much smaller than the wavelength of the carrier signal (thus preventing a standing wave from de- veloping within the antenna). In the near-field (approx- imately one quarter of a wavelength)[1] the antenna can produce either an electric field, or a magnetic field, but not an electromagnetic field. Thus NFC communicates either practice a metre or more. If the antenna is just a few by a modulated electric field, or a modulated magnetic centimetres long, it will only set up the ‘near-field’ around field, but not by radio (electromagnetic waves). For ex- [2] itself, with length, width and depth of the field roughly the ample, a small loop antenna (also known as a magnetic same as the dimensions of the antenna. Very little energy loop) produces a magnetic field, which can then be picked will radiate away, it is essentially a stationary electromag- up by another small loop antenna, if it is near enough. netic field pulsating at 13.56 MHz. If another similarly Magnetic NFC has a useful property of being able to pen- small antenna comes into this field, it will induce an elec- etrate conductors[3] that would reflect radio waves. tric potential into it, alternating at the same frequency. Many mobile phones now use electric-field NFC (oper- By modulating the signal in the active antenna, one can ating at a frequency of 13.56 MHz, corresponding to a transmit a signal to the passive, receiving antenna. wavelength of 22.11 m) for certain special transactions Present and anticipated applications include contactless because the very short range of NFC makes it difficult to transactions, data exchange, and simplified setup of more eavesdrop on. To efficiently generate a far-field, which complex communications such as Wi-Fi.[4] Communica- means to send out radio waves of this wavelength, one tion is also possible between an NFC device and an un- typically needs an antenna of a quarter wavelength, in powered NFC chip, called a “tag”.[5] 1 2 1 USES devices,[5] it is also capable of replacing earlier one-way applications. 1.1 Commerce NFC devices can be used in contactless payment sys- tems, similar to those currently used in credit cards and electronic ticket smartcards, and allow mobile payment to replace or supplement these systems. With the release of Android 4.4, Google introduced a new platform support for secure NFC-based transactions through Host Card Emulation (HCE),[6] for payments, loyalty programs, card access, transit passes, and other custom services. With HCE, any app on an Android 4.4 device can emulate an NFC smart card, letting users tap to initiate transactions with an app of their choice. Apps can also use a new Reader Mode so as to act as readers for HCE cards and other NFC-based transactions. On September 9, 2014, Apple also announced support for NFC-powered transactions as part of their Apple Pay program.[7] Apple stated that their version of NFC pay- ment is more secure than competitors because Apple Pay An NFC enabled parking meter label used by the city of San implements tokenization of its data in order to encrypt it Francisco for payment and phone reminders of time remaining. and protect it from unauthorized use.[8] Developed by Cellotape/Tap4Mor. 1.2 Bootstrapping other connections NFC offers a low-speed connection with extremely sim- ple setup, and can be used to bootstrap more capable wireless connections.[9] For example, the Android Beam software uses NFC to complete the steps of enabling, pairing and establishing a Bluetooth connection when do- ing a file transfer, disabling Bluetooth automatically on both devices once the desired task has completed.[10] Nokia, Samsung, BlackBerry and Sony[11] have used NFC technology to pair Bluetooth headsets, media play- ers, and speakers with one tap in its NFC-enabled de- vices. The same principle can be applied to the con- figuration of Wi-Fi networks. This only works between Android devices version Jelly Bean and above. Samsung N-Mark Logo for NFC-enabled Devices Galaxy devices have a feature named S-Beam, an exten- sion of Android Beam that uses NFC (to share MAC Address and IP addresses) and then uses WiFi Direct to 1 Uses share files and documents. The advantage of using WiFi Direct over Bluetooth is that it permits much faster data NFC builds upon RFID systems by allowing two-way transfers, having a speed of up to 300Mbit/s for sharing communication between endpoints, where earlier sys- large files.[12] tems such as contactless smart cards were one-way only. It has been used in devices such as Google Nexus since the Nexus S, but wasn't really used until Android 4.0 1.3 Social networking Ice Cream Sandwich was released with a feature called "Android Beam" which was first introduced with the NFC can be used in social networking situations, such as Galaxy Nexus. sharing contacts, photos, videos or files,[13] and entering Since unpowered NFC “tags” can also be read by NFC multiplayer mobile games.[14] 3 1.4 Identity and access tokens • 2009 In January, NFC Forum released Peer-to-Peer standards to transfer contact, URL, initiate Blue- The NFC Forum promotes the potential for NFC-enabled tooth, etc.[22] devices to act as electronic identity documents and keycards.[9] As NFC has a short range and supports en- • 2010 Samsung Nexus S: First Android NFC phone cryption, it may be more suitable than earlier, less private shown[23][24] RFID systems. • 2010 The city of Nice in Southern France launches the “Nice City of contactless mobile” project, pro- 1.5 Smartphone automation and NFC tags viding inhabitants with new NFC generation mobile phones and bank cards, and a real “bouquet of ser- Smartphones equipped with NFC can be paired with vices” for their daily lives covering transportation, NFC Tags or stickers which can be programmed by NFC tourism and student’s services apps to automate tasks. These programs can allow for a change of phone settings, a text to be created and sent, an • 2011 Tapit Media launches in Sydney Australia as app to be launched, or any number of commands to be the first specialized NFC marketing company executed, limited only by the NFC app and other apps on • the smartphone. 2011 Google I/O “How to NFC” demonstrates NFC to initiate a game and to share a contact, URL, app, These applications are perhaps the most practical current video, etc.[13] uses for NFC since it does not rely on a company or man- ufacturer but can be utilized immediately by anyone any- • 2011 NFC support becomes part of the Symbian where with an NFC-equipped smartphone and an NFC mobile operating system with the release of Sym- tag.[15] bian Anna version.[25] • 2011 Research In Motion is the first company for its 1.6 Gaming devices to be certified by MasterCard Worldwide, the functionality of PayPass[26] See also: List of gaming NFC platforms • 2012 March. EAT., a well-known UK restaurant NFC has been used in video games starting with chain, and Everything Everywhere (Orange Mobile Skylanders: Spyro’s Adventure. With it you buy figurines Network Operator), partner on the UK’s first na- which are customizable and contain personal data with tionwide NFC-enabled smartposter campaign, led each figure, so no two figures are exactly alike. The Wii by René Batsford, head of ICT for EAT., also U is the first system to include NFC technology out of the known for deploying the UK’s first nationwide con- box. tactless payment solution in 2008. A specially cre- ated mobile phone app is triggered when the NFC enabled mobile phone comes into contact with the [27] 2 History smartposter. • 2012 Sony introduces the “Smart Tags”, which use NFC traces its roots back to radio-frequency identifica- NFC technology to change modes and profiles on tion, or RFID. RFID allows a reader to send radio waves a Sony smartphone at close range, included in the to a passive electronic tag for identification, authentica- package of (and “perfectly paired” with) the Sony tion and tracking. Xperia P Smartphone released the same year.[28] • [29] • 1983 The first patent to be associated with the ab- 2012 Samsung introduces TecTile; a set of breviation RFID was granted to Charles Walton.[16] MIFARE NFC stickers and a companion applica- tion for Android to read and write the TecTile stick- • 2002 Sony and Philips agreed on establishing a new ers, and design macros that can be triggered by them. technology specification and created a technical out- line on March 25, 2002.[17] • 2013 Samsung and Visa announce major partner- ship to develop mobile payments. • 2004 Nokia, Philips and Sony established the Near Field Communication (NFC) Forum[18] • 2013 IBM Scientists from Zurich, in an effort to curb fraud and security breaches have come up with • [19] 2006 Initial specifications for NFC Tags a new mobile authentication security technology • 2006 Specification for “SmartPoster” records[20] based on Near-Field Communication (NFC). IBM’s new technology works on similar principles to that • 2006 Nokia 6131 was the first NFC phone[21] of a dual-factor authentication security measure.[30] 4 3 STANDARDS • 2014 Apple Inc. announces Apple Pay, an NFC pay- NFC tags contain data and are typically read-only, but ment feature for the iPhone 6, iPhone 6 Plus and may be rewriteable.
Recommended publications
  • Design of a System for Cm-Range Wireless Communication
    Design of a system for cm-range wireless communication Simone Gambini Jan M. Rabaey Elad Alon Electrical Engineering and Computer Sciences University of California at Berkeley Technical Report No. UCB/EECS-2009-184 http://www.eecs.berkeley.edu/Pubs/TechRpts/2009/EECS-2009-184.html December 18, 2009 Copyright © 2009, by the author(s). All rights reserved. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission. Design of a system for cm-range wireless communications by Simone Gambini A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Electrical Engineeing and Computer Sciences in the GRADUATE DIVISION of the UNIVERSITY OF CALIFORNIA, BERKELEY Committee in charge: Professor Jan Rabey, Chair Professor Elad Alon Professor Paul K. Wright Fall 2009 The dissertation of Simone Gambini is approved. Chair Date Date Date University of California, Berkeley Fall 2009 Design of a system for cm-range wireless communications Copyright c 2009 by Simone Gambini Abstract Design of a system for cm-range wireless communications by Simone Gambini Doctor of Philosophy in Electrical Engineeing and Computer Sciences University of California, Berkeley Professor Jan Rabey, Chair The continuous growth in the number of mobile phone subscribers, which exceeded 3 billions by 2007 , and of the number of wireless devices and systems, led to visions of a near future in which wireless technology is so ubiquitous that 1000 Radios per person will exist.
    [Show full text]
  • Antenna Gain Measurement Using Image Theory
    i ANTENNA GAIN MEASUREMENT USING IMAGE THEORY SANDRAWARMAN A/L BALASUNDRAM A project report submitted in partial fulfillment of the requirement for the award of the degree Master of Electrical Engineering Faculty of Electrical and Electronic Engineering Universiti Tun Hussein Onn Malaysia JANUARY 2014 v ABSTRACT This report presents the measurement result of a passive horn antenna gain by only using metallic reflector and vector network analyzer, according to image theory. This method is an alternative way to conventional methods such as the three antennas method and the two antennas method. The gain values are calculated using a simple formula using the distance between the antenna and reflector, operating frequency, S- parameter and speed of light. The antenna is directed towards an absorber and then directed towards the reflector to obtain the S11 parameter using the vector network analyzer. The experiments are performed in three locations which are in the shielding room, anechoic chamber and open space with distances of 0.5m, 1m, 2m, 3m and 4m. The results calculated are compared and analyzed with the manufacture’s data. The calculated data have the best similarities with the manufacturer data at distance of 0.5m for the anechoic chamber with correlation coefficient of 0.93 and at a distance of 1m for the shield room and open space with correlation coefficient of 0.79 and 0.77 but distort at distances of 2m, 3m and 4m at all of the three places. This proves that the single antenna method using image theory needs less space, time and cost to perform it.
    [Show full text]
  • Smart Cards Contents
    Smart cards Contents 1 Smart card 1 1.1 History ................................................ 1 1.1.1 Invention ........................................... 1 1.1.2 Carte Bleue .......................................... 2 1.1.3 EMV ............................................. 2 1.1.4 Development of contactless systems ............................. 2 1.2 Design ................................................ 2 1.2.1 Contact smart cards ..................................... 3 1.2.2 Contactless smart cards .................................... 3 1.2.3 Hybrids ............................................ 4 1.3 Applications .............................................. 4 1.3.1 Financial ........................................... 4 1.3.2 SIM .............................................. 4 1.3.3 Identification ......................................... 4 1.3.4 Public transit ......................................... 5 1.3.5 Computer security ...................................... 6 1.3.6 Schools ............................................ 6 1.3.7 Healthcare .......................................... 6 1.3.8 Other uses .......................................... 6 1.3.9 Multiple-use systems ..................................... 6 1.4 Security ................................................ 6 1.5 Benefits ................................................ 6 1.6 Problems ............................................... 7 1.7 See also ................................................ 7 1.8 Further reading ...........................................
    [Show full text]
  • Design of a Class of Antennas Utilizing MEMS, EBG and Septum Polarizers Including Near-Field Coupling Analysis
    UNIVERSITY OF CALIFORNIA Los Angeles Design of a Class of Antennas Utilizing MEMS, EBG and Septum Polarizers including Near-field Coupling Analysis A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Electrical Engineering by Ilkyu Kim 2012 c Copyright by Ilkyu Kim 2012 ABSTRACT OF THE DISSERTATION Design of a Class of Antennas Utilizing MEMS, EBG and Septum Polarizers including Near-field Coupling Analysis by Ilkyu Kim Doctor of Philosophy in Electrical Engineering University of California, Los Angeles, 2012 Professor Yahya Rahmat-Samii, Chair Recent developments in mobile communications have led to an increased appearance of short-range communications and high data-rate signal transmission. New technologies provides the need for an accurate near-field coupling analysis and novel antenna designs. An ability to effectively estimate the coupling within the near-field region is required to realize short-range communications. Currently, two common techniques that are applicable to the near-field coupling problem are 1) integral form of coupling formula and 2) generalized Friis formula. These formulas are investigated with an emphasis on straightforward calculation and accuracy for various distances between the two antennas. The coupling formulas are computed for a variety of antennas, and several antenna configurations are evaluated through full-wave simulation and indoor measurement in order to validate these techniques. In addition, this research aims to design multi- functional and high performance antennas based on MEMS (Microelectromechanical ii Systems) switches, EBG (Electromagnetic Bandgap) structures, and septum polarizers. A MEMS switch is incorporated into a slot loaded patch antenna to attain frequency reconfigurability.
    [Show full text]
  • A Prototype Model Design of Wideband Standard Reference Rod- Dipole Antenna for 3-Axial EMC Measurement with Hybrid Balun for 0.9 to 3.2Ghz Range
    ADVANCED ELECTROMAGNETICS, VOL. 7, NO. 1, FEBRUARY 2018 A Prototype Model Design of Wideband Standard Reference Rod- Dipole Antenna for 3-Axial EMC Measurement with Hybrid Balun for 0.9 to 3.2GHz Range. Sarang Patil1, Peter Petkov2, Boncho Bonev3 1SKN Sinhgad Institute of Technology & Science, Lonavala, Maharashtra, India 2, 3 Department of RCVT, Technical University of Sofia, Sofia, Bulgaria E-mail: [email protected] Abstract Compliance test at open field site testing for manufacturing Every electronics equipment must deal with EMC test. The end. testing laboratory of electronics equipment for radiation emission must have accurately calibrated antennas. The To measure all three components of electric field vector, a field strength of total radiated radio frequency is average of tailor-made antenna type called "Tri-pole" is most beneficial all incident signals at given point; this incident signal over conventional antenna; different EM wave field was originates from various directions. To measure three measuring antenna with the comparison is discussed in components of all-electric field vectors, a tri-pole antenna is previous work [1].The simple structure symmetric balanced most beneficial over conventional antenna because of it half-wave dipole used for various applications, it provides responds to signal coming from multi-directions. This paper useful electrical characteristics but a narrow band, this presents novel three axis wideband calculable rod-dipole problem is solved in [2]. antenna with the hybrid balun for the range of 900MHz to 3.2GHz frequencies, the proposed antenna is small in size Antenna designing is the hot topic for E-field probe, various and functional electrical characteristics.
    [Show full text]
  • Near Field Quasi-Null Control and Far Field Sidelobe Level Maintenance
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Repositorio da Universidade da Coruña NEAR FIELD QUASI-NULL CONTROL WITH FAR FIELD SIDELOBE LEVEL MAINTENANCE IN LINE SOURCE DISTRIBUTIONS J. C. Brégains, F. Ares, and E. Moreno Grupo de Sistemas Radiantes, Departamento de Física Aplicada, Facultad de Física, Universidad de Santiago de Compostela. 15782 - Santiago de Compostela – Spain [email protected] ABSTRACT An improving method -based on Taylor line source- that allocates a quasi-null in a specified angular position of near field pattern, and, simultaneously, controls the general topography of far-field sidelobe level -without significantly loss of directivity, compared with optimal effi- ciency Taylor distribution, of the latter- is presented in this article. The method is based on the application of the Simulated Annealing technique, by achieving the complex roots of the pattern distribution. An example developed below demonstrates this accomplishment. 1. INTRODUCTION In some antenna applications it is necessary the reduction of the field magnitude in a particu- lar angular position; either, for example, to avoid the radiation in a certain specific direction, or the reception of the signal in order to keep it away from some interference, null controlling is widely applied by antenna’s designers. Previous papers [1-3] indicate that some authors 1 have achieved null controlling or steering but only using far field patterns. These examples do not face the problem of near field radiation (or reception), so the named results have not the capability neither to avoid the perturbation caused by obstacles close to the antenna, nor radi- ating with undesired relatively high power in an certain angular position at the neighborhood of it.
    [Show full text]
  • How to Measure All Types of Antennas Using Very-Near-Field Measurement by Ruska Patton, Director, Product Management and Ning Yang, Principal Antenna Engineer
    How to Measure All Types of Antennas Using Very-Near-Field Measurement by Ruska Patton, Director, Product Management and Ning Yang, Principal Antenna Engineer RFxpert test result CTIA Chamber test result How to Measure All Types of Antennas Using Very-Near-Field Measurement Introduction Antennas that fail to meet specified design criteria, regulatory requirements or consumer satisfaction either rapidly find the scrap heap or cause costly delays. If the antenna in question actually makes it to market and consumers identify a problem, it can create a widespread public relations nightmare. Designers therefore need to characterize an antenna to meet performance criteria including desired frequency, gain, bandwidth, impedance, efficiency and polarization. Traditional antenna characterization requires full-fledged far-field testing or gathering near-field data sets to project far-field patterns. Unfortunately, the planar sampling mode, the fastest and least costly traditional near- or far-field technique, only generates reliable results for directional antennas. Omnidirectional antennas must currently be sampled in spherical mode in a sufficiently large shielded test chamber to overcome potential sensor coupling. For an omnidirectional antenna under test (AUT), such a system also requires a three-axis (X, Y, and Z) robot system and many sampling points. Every traditional antenna testing method thus requires a trained technician and a large shielded chamber. These requirements prove costly both as a capital outlay and an ongoing operations expense. To overcome these hurdles, a novel very-near-field technology based on a probe array samples the AUT on a plane surface at a distance of 2.5 cm. The AUT can be either directional or omnidirectional.
    [Show full text]
  • Guest Editorial Special Issue on IEEE RFID 2018 Conference
    IEEE JOURNAL OF RADIO FREQUENCY IDENTIFICATION, VOL. 3, NO. 1, MARCH 2019 1 Guest Editorial Special Issue on IEEE RFID 2018 Conference ADIO Frequency Identification (RFID) is a generic term and 3500 IEEE journal and conference publications (all with R for a variety of active and passive RF technologies the term “RFID” in their titles), which serve to underline the that wirelessly convey object identification information. RFID rapid growth of the field. technologies encompass multiple frequency bands and differ- In 2017, IEEE launched a new IEEE JOURNAL OF RADIO ent mechanisms of information transfer: Low Frequency (LF) FREQUENCY IDENTIFICATION (JRFID). Each year, the jour- and High Frequency (HF) RFID tags typically use inductive nal features a special issue that presents a collection of coupling, Ultra-High Frequency (UHF) and microwave RFID extended papers from that year’s IEEE RFID conference. typically use electromagnetic wave propagation although they Papers in this special issue are extended versions of paper and often operate in near-field application scenarios as well. RFID poster presentations that were featured in IEEE RFID 2018, transponders have varying degrees of sophistication and their a highly competitive premier technical conference on RFID design is often a tradeoff between functionality and cost. At that took place in Orlando, FL on April 10-12, 2018. The one end of the spectrum, there are active RFID tags that offer four papers presented in this issue are written by researchers on-board battery and memory, sensor integration, active RF from three countries: Germany, India and the USA. The top- transmitter and hence communication range up to kilometers ics of this paper include crowd size estimation, antenna design albeit at increased costs.
    [Show full text]
  • Measurement of Loudspeaker Directivity
    KLIPPEL E-learning, training 8 2018-12-19 Hands-On Training 8 Measurement of Loudspeaker Directivity 1. Objective of the Hands-on Training - Understanding the need for assessing loudspeaker directivity - Introducing the basic theory of acoustic holography and field separation - Applying Near Field Scanning techniques to loudspeakers - Interpreting the results of Near Field Scanning - Developing skills for performing practical measurements 2. Requirements 2.1. Previous Knowledge of the Participants It is recommended to do the Klippel Training #2 “Vibration and Radiation Behavior of Loudspeaker’s Membrane” before starting this training. 2.2. Minimum Requirements The objectives of the hands-on training can be accomplished by using the results of the measurement provided in a Klippel database (.kdbx) dispensing with a complete setup of the KLIPPEL measurement hardware. The data may be viewed by downloading the measurement software dB-Lab from www.klippel.de/training and installing them on a Windows PC. 2.3. Optional Requirements If the participants have access to a KLIPPEL Analyzer System, we recommend to perform some additional measurements on loudspeakers provided by instructor or by the participants. In order to perform these measurements, you will also need the following additional software and hardware components: Klippel Robotics KLIPPEL Analyzer (DA2 or KA3) Near Field Scanner Amplifier Microphone 3. The Training Process Read the following theory to refresh your knowledge required for the training. Watch the demo video to learn about the practical aspects of the measurement. Answer the preparatory questions to check your understanding. Follow the instructions to interpret the results in the database and answer the multiple- choice questions off-line.
    [Show full text]
  • Field Optimization Using Segmented Patch Antennas at High Frequencies
    International Journal of Recent Technology and Engineering (IJRTE) ISSN: 2277-3878, Volume-8 Issue-4, November 2019 Field Optimization using Segmented Patch Antennas at High Frequencies Mohammed Nayeemuddin, P. Karpagavalli there are many more research operations going on in Abstract: in recent day’s communication technology has this field for further reducing the antenna bandwidth, gain, increased in every field where in antenna propagation magnetic distribution of field, polarized operation and many transmission of signals to the other end is dependent on more parameters are considered. antennas. This propagation should be appropriate in both the fields as near and far fields for effectively covering which RFIDs are used which abbreviate as radio frequency identification II. ANTENNA DESIGN which are considered as reader antenna developed for operating For near field systems of RFID we use these Loop in near and far fields with high frequency band range. Here in this paper segmented loop designed of patch antenna is antennas commonly for inductive coupling. For making developed and the fabrication of antenna is done where the this loop electrically small at both the frequencies such as frequency range will be 900 MHz approximately with coefficient low and high band where its very minimum to use physical of reflection as less than 8dB which covers major UHB loop. Among the amplitude and phase distribution of frequency range of band. It has linearly polarized pattern of current is common with such a loop is uniform. So, near radiation which provides gain of 6dBi and the capacity of the loop an uniform and strong magnetic field is produced reading of antenna is from 12-15m for both the applications of in near region of loop.
    [Show full text]
  • Compact Loop Antenna for Near-Field and Far-Field Uhf Rfid Applications
    Progress In Electromagnetics Research C, Vol. 37, 171{182, 2013 COMPACT LOOP ANTENNA FOR NEAR-FIELD AND FAR-FIELD UHF RFID APPLICATIONS Xiaozheng Lai1, *, Zeming Xie2, and Xuanliang Cen2 1School of Computer Science & Engineering, South China University of Technology, Guangzhou 510006, China 2School of Electronic & Information, South China University of Technology, Guangzhou 510641, China Abstract|A novel type of radio frequency identi¯cation (RFID) reader antenna is proposed for mobile ultra-high frequency (UHF) RFID device. By folded-dipole loop structure with parasitic element, a small antenna size of 31 ¤ 31 ¤ 1:6 mm3 is achieved. The antenna with di®erent parasitic element size can work on di®erent UHF RFID bands. The antenna prototype is fabricated and the measured bandwidth is around 13.5 MHz (915.5{929 MHz), which covers the China RFID Band (920{925 MHz). The measured reading distance achieves 65 mm with the near-¯eld RFID tag and 1.17 m with the far-¯eld tag. The measurement agrees well with simulated result and shows that antenna is desirable for both near-¯eld and far-¯eld UHF RFID applications. 1. INTRODUCTION Radio-frequency-identi¯cation (RFID) technology has received a lot of attention in warehouse, supply chain, industry, and commerce [1]. As RFID deployment moves from pallet level to item level, it is necessary to identify and track objects by RFID tags at anytime and anywhere. Then, mobile RFID device has advantages in terms of cost, portability and wireless communication. Mobile RFID device is de¯ned as a compact RFID reader into a mobile phone, which provides diverse services through mobile communication networks [2].
    [Show full text]
  • Basics of Antennas (And Transmission Lines)
    Basics of Antennas (and Transmission Lines) Presented to IEEE EMC Society EMC Basics + Workshop February 6 2019 by Mark A. Steffka email: [email protected] 1 Introduction • This discussion covers several key aspects of antenna engineering (and transmission lines): – Theory – Practical antenna design techniques – Overview of actual antennas – Goal is to enable you to: • Understand antenna basics • Know that it’s possible to EFFICIENTLY design, model, select and/or evaluate effective antennas • Understand transmission line fundamentals. 2 The “Source-Path-Receiver” Electromagnetic Interaction • The path of the energy to the receiver may be via radiation or conduction. • If path is radiated, the intensity is reduced as a function of distance (similar to a flashlight )- the intensity is lower the greater the distance away - the “inverse distance” property. 3 Electromagnetic Frequency Bands • Much of today’s communication occurs from MF to UHF. • MF/VHF/UHF used for broadcasting. • UHF is used for handheld and mobile devices (phones, Wi- Fi). 4 Terminology in EMC – RF Signals • Radio Frequency (RF) – E/M wave frequencies used typically for communication. • kHz – 1 x 10^3 Hertz (cycles per second) • MHz – 1 x 10 ^6 Hertz • GHz – “1000 MHz”, or 1 x 10^6 Hertz • THz – 1 x 10^12 Hertz 5 Circuit Theory Truths and Lie • Every current must return to it’s source. • The path of the “source” and “return” current should be determined. • Current “takes the path of least” __________________. 6 Circuit Theory Truths and Lie • TRUTH: Every current must return to it’s source. • The path of the “source” and “return” current should be determined.
    [Show full text]