Antenna Reference Guide
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Radiometry and the Friis Transmission Equation Joseph A
Radiometry and the Friis transmission equation Joseph A. Shaw Citation: Am. J. Phys. 81, 33 (2013); doi: 10.1119/1.4755780 View online: http://dx.doi.org/10.1119/1.4755780 View Table of Contents: http://ajp.aapt.org/resource/1/AJPIAS/v81/i1 Published by the American Association of Physics Teachers Related Articles The reciprocal relation of mutual inductance in a coupled circuit system Am. J. Phys. 80, 840 (2012) Teaching solar cell I-V characteristics using SPICE Am. J. Phys. 79, 1232 (2011) A digital oscilloscope setup for the measurement of a transistor’s characteristic curves Am. J. Phys. 78, 1425 (2010) A low cost, modular, and physiologically inspired electronic neuron Am. J. Phys. 78, 1297 (2010) Spreadsheet lock-in amplifier Am. J. Phys. 78, 1227 (2010) Additional information on Am. J. Phys. Journal Homepage: http://ajp.aapt.org/ Journal Information: http://ajp.aapt.org/about/about_the_journal Top downloads: http://ajp.aapt.org/most_downloaded Information for Authors: http://ajp.dickinson.edu/Contributors/contGenInfo.html Downloaded 07 Jan 2013 to 153.90.120.11. Redistribution subject to AAPT license or copyright; see http://ajp.aapt.org/authors/copyright_permission Radiometry and the Friis transmission equation Joseph A. Shaw Department of Electrical & Computer Engineering, Montana State University, Bozeman, Montana 59717 (Received 1 July 2011; accepted 13 September 2012) To more effectively tailor courses involving antennas, wireless communications, optics, and applied electromagnetics to a mixed audience of engineering and physics students, the Friis transmission equation—which quantifies the power received in a free-space communication link—is developed from principles of optical radiometry and scalar diffraction. -
25. Antennas II
25. Antennas II Radiation patterns Beyond the Hertzian dipole - superposition Directivity and antenna gain More complicated antennas Impedance matching Reminder: Hertzian dipole The Hertzian dipole is a linear d << antenna which is much shorter than the free-space wavelength: V(t) Far field: jk0 r j t 00Id e ˆ Er,, t j sin 4 r Radiation resistance: 2 d 2 RZ rad 3 0 2 where Z 000 377 is the impedance of free space. R Radiation efficiency: rad (typically is small because d << ) RRrad Ohmic Radiation patterns Antennas do not radiate power equally in all directions. For a linear dipole, no power is radiated along the antenna’s axis ( = 0). 222 2 I 00Idsin 0 ˆ 330 30 Sr, 22 32 cr 0 300 60 We’ve seen this picture before… 270 90 Such polar plots of far-field power vs. angle 240 120 210 150 are known as ‘radiation patterns’. 180 Note that this picture is only a 2D slice of a 3D pattern. E-plane pattern: the 2D slice displaying the plane which contains the electric field vectors. H-plane pattern: the 2D slice displaying the plane which contains the magnetic field vectors. Radiation patterns – Hertzian dipole z y E-plane radiation pattern y x 3D cutaway view H-plane radiation pattern Beyond the Hertzian dipole: longer antennas All of the results we’ve derived so far apply only in the situation where the antenna is short, i.e., d << . That assumption allowed us to say that the current in the antenna was independent of position along the antenna, depending only on time: I(t) = I0 cos(t) no z dependence! For longer antennas, this is no longer true. -
Design and Application of a New Planar Balun
DESIGN AND APPLICATION OF A NEW PLANAR BALUN Younes Mohamed Thesis Prepared for the Degree of MASTER OF SCIENCE UNIVERSITY OF NORTH TEXAS May 2014 APPROVED: Shengli Fu, Major Professor and Interim Chair of the Department of Electrical Engineering Hualiang Zhang, Co-Major Professor Hyoung Soo Kim, Committee Member Costas Tsatsoulis, Dean of the College of Engineering Mark Wardell, Dean of the Toulouse Graduate School Mohamed, Younes. Design and Application of a New Planar Balun. Master of Science (Electrical Engineering), May 2014, 41 pp., 2 tables, 29 figures, references, 21 titles. The baluns are the key components in balanced circuits such balanced mixers, frequency multipliers, push–pull amplifiers, and antennas. Most of these applications have become more integrated which demands the baluns to be in compact size and low cost. In this thesis, a new approach about the design of planar balun is presented where the 4-port symmetrical network with one port terminated by open circuit is first analyzed by using even- and odd-mode excitations. With full design equations, the proposed balun presents perfect balanced output and good input matching and the measurement results make a good agreement with the simulations. Second, Yagi-Uda antenna is also introduced as an entry to fully understand the quasi-Yagi antenna. Both of the antennas have the same design requirements and present the radiation properties. The arrangement of the antenna’s elements and the end-fire radiation property of the antenna have been presented. Finally, the quasi-Yagi antenna is used as an application of the balun where the proposed balun is employed to feed a quasi-Yagi antenna. -
Antenna Selection Guide by Richard Wallace
Application Note AN058 Antenna Selection Guide By Richard Wallace Keywords • Antenna Selection • 433 MHz (387 – 510 MHz) Antenna • Anechoic Chamber • 868 MHz (779 – 960 MHz) Antenna • Antenna Parameters • 915 MHz (779 – 960 MHz) Antenna • 169 MHz (136 – 240 MHz) Antenna • 2.4 GHz Antenna • 315 MHz (273 – 348 MHz) Antenna • CC-Antenna-DK 1 Introduction This application note describes important In addition different antenna types are parameters to consider when deciding presented, with their pros and cons. All of what kind of antenna to use in a short the antenna reference designs available range device application. on www.ti.com/lpw are presented including the Antenna Development Kit Important antenna parameters, different [29]. antenna types, design aspects and techniques for characterizing antennas are The last section in this document contains presented. Radiation pattern, gain, references to additional antenna impedance matching, bandwidth, size and resources such as literature, applicable cost are some of the parameters EM simulation tools and a list of antenna discussed in this document. manufacturer and consultants. Antenna theory and practical Correct choice of antenna will improve measurement are also covered. system performance and reduce the cost. Figure 1. Texas Instruments Antenna Development Kit (CC-Antenna-DK) SWRA161B Page 1 of 44 Application Note AN058 Table of Contents KEYWORDS 1 1 INTRODUCTION 1 2 ABBREVIATIONS 3 3 BRIEF ANTENNA THEORY 4 3.1 DIPOLE (Λ/2) ANTENNAS 4 3.2 MONOPOLE (Λ/4) ANTENNAS 5 3.3 WAVELENGTH CALCULATIONS -
Compact Integrated Antennas Designs and Applications for the Mc1321x, Mc1322x, and Mc1323x
Freescale Semiconductor Document Number: AN2731 Application Note Rev. 2, 12/2012 Compact Integrated Antennas Designs and Applications for the MC1321x, MC1322x, and MC1323x 1 Introduction Contents 1 Introduction . 1 With the introduction of many applications into the 2 Antenna Terms . 2 2.4 GHz band for commercial and consumer use, 3 Basic Antenna Theory . 3 Antenna design has become a stumbling point for many 4 Impedance Matching . 5 customers. Moving energy across a substrate by use of an 5 Antennas . 8 RF signal is very different than moving a low frequency 6 Miniaturization Trade-offs . 11 voltage across the same substrate. Therefore, designers 7 Potential Issues . 12 who lack RF expertise can avoid pitfalls by simply 8 Recommended Antenna Designs . 13 following “good” RF practices when doing a board 9 Design Examples . 14 layout for 802.15.4 applications. The design and layout of antennas is an extension of that practice. This application note will provide some of that basic insight on board layout and antenna design to improve our customers’ first pass success. Antenna design is a function of frequency, application, board area, range, and costs. Whether your application requires the absolute minimum costs or minimization of board area or maximum range, it is important to understand the critical parameters so that the proper trade-offs can be chosen. Some of the parameters necessary in selecting the correct antenna are: antenna © Freescale Semiconductor, Inc., 2005, 2006, 2012. All rights reserved. tuning, matching, gain/loss, and required radiation pattern. This note is not an exhaustive inquiry into antenna design. It is instead, focused toward helping our customers understand enough board layout and antenna basics to aid in selecting the correct antenna type for their application as well as avoiding the typical layout mistakes that cause performance issues that lead to delays. -
Antenna Articles Collection of Short Articles Relating to All Manners of Antennas
Antenna Tips page 1 of 31 Source : http://www.funet.fi/pub/dx/text/antennas/antinfo.txt Antenna Articles Collection of short articles relating to all manners of antennas. These articles are the hard work of Wayne Sarosi KB4YLY (995 Alabama Street, Titusville, FL 32796) SUBJECT: Circular Polarized Antenna There has been a request for a series on 'CP' antennas. The term 'CP' eluded me at first as I was not familar with the abriviated designator for circular polarization. At work, we just use the entire words. I'm going to begin this ten part series with the basics. After researching CP designs with a few engineers and fellow hams, I found that they knew very little about the subject. I also found I didn't know quite as much as I thought I did about circular polarization. So starting at the begining will help all out. First, let's discuss the circular polarized wave. There seems to be conflicting standards used by the world of physics and the IEEE. I found this to be true in four reference manuals including the ARRL Antenna Handbook. At least it's stated right up front but biased according to which text you read. We will follow the IEEE/ARRL standard in the following series for obvious reasons. There are two types of circular polarization; right and left. All of us agree up to this point. According to the ARRL Antenna Handbook, the following statement: 'Polarization Sense is a critical factor, especially in EME work or if the satellite uses a circular polarized antenna. -
AB Antenna Family.Qxp
WIRELESS PRODUCTS Airborne™ Antenna Product Family ACH2-AT-DP000 series ACH0-CD-DP000 series (other accessories) Airborne™ Antennas are designed for connection to 802.11 wireless devices operating in the 2.4GHz ISM band. These antennas fully support the entire line of Airborne™ wireless 802.11 products. This assortment of antennas is intended to provide OEMs with solutions that meet the demanding and diverse requirements for transportation, medical, warehouse logistics, POS, industrial, military and scientific applications. Applications The Airborne™ Antenna family offers antennas for embedded applications, fixed stations, mobile operation and client side devices, and for indoor and outdoor applications. The antennas feature RP-SMA, N-type and U.FL connectors that provide the designer with flexible ways to connect to Airborne wireless products. A wide range of antenna types and gain options enable an OEM to select the antenna that best matches their application requirements. The Recommended for AirborneTM 802.11 lower gain and smaller antennas, such as the “rubber duck” antennas, would fit applications embedded and system bridge products where the range is not required to exceed 200- 400m while the higher gain directional antennas Made for Embedded or External mounting, would be suitable for extended range that require greater than 800m reach. Embedded antennas Mobile or Fixed station, and Indoor and/or provide ranges from 50m up to 300m. Outdoor operation Specialty Antenna Embedded antenna options are intended for Select from Omni Directional, Highly applications where it is not desirable to use an Directional, or Corner Reflector external antenna, or where the enclosure or application does not allow for an external antenna. -
ANTENNA INTRODUCTION / BASICS Rules of Thumb
ANTENNA INTRODUCTION / BASICS Rules of Thumb: 1. The Gain of an antenna with losses is given by: Where BW are the elev & az another is: 2 and N 4B0A 0 ' Efficiency beamwidths in degrees. G • Where For approximating an antenna pattern with: 2 A ' Physical aperture area ' X 0 8 G (1) A rectangle; X'41253,0 '0.7 ' BW BW typical 8 wavelength N 2 ' ' (2) An ellipsoid; X 52525,0typical 0.55 2. Gain of rectangular X-Band Aperture G = 1.4 LW Where: Length (L) and Width (W) are in cm 3. Gain of Circular X-Band Aperture 3 dB Beamwidth G = d20 Where: d = antenna diameter in cm 0 = aperture efficiency .5 power 4. Gain of an isotropic antenna radiating in a uniform spherical pattern is one (0 dB). .707 voltage 5. Antenna with a 20 degree beamwidth has a 20 dB gain. 6. 3 dB beamwidth is approximately equal to the angle from the peak of the power to Peak power Antenna the first null (see figure at right). to first null Radiation Pattern 708 7. Parabolic Antenna Beamwidth: BW ' d Where: BW = antenna beamwidth; 8 = wavelength; d = antenna diameter. The antenna equations which follow relate to Figure 1 as a typical antenna. In Figure 1, BWN is the azimuth beamwidth and BW2 is the elevation beamwidth. Beamwidth is normally measured at the half-power or -3 dB point of the main lobe unless otherwise specified. See Glossary. The gain or directivity of an antenna is the ratio of the radiation BWN BW2 intensity in a given direction to the radiation intensity averaged over Azimuth and Elevation Beamwidths all directions. -
Radiation Pattern, Gain, and Directivity James Mclean, Robert Sutton, Rob Hoffman, TDK RF Solutions
Interpreting Antenna Performance Parameters for EMC Applications: Part 2: Radiation Pattern, Gain, and Directivity James McLean, Robert Sutton, Rob Hoffman, TDK RF Solutions This article is the second in a three-part tutorial series covering antenna terminology. As noted in the first part, a great deal of effort has been made over the years to standardize antenna terminology. The de facto standard is the IEEE Standard Definitions of Terms for Antennas, published in 1983. However, the EMC community has developed its own distinct vernacular which contains terms not included in the IEEE standard. In the first part of this series, we discussed radiation efficiency and input impedance match. In the second part of this series, we will discuss antenna field regions and antenna gain and how they relate to EMC measurements. Geometrical Considerations In order to quantitatively discuss radiation from antennas, it is necessary to first specify a coordinate system for describing the antenna and the associated electromagnetic fields. The most natural coordinate system for this task is the spherical coordinate system. This is because at a sufficient distance from an antenna (or any localized source of electromagnetic radiation), the electromagnetic fields must decay inversely with radial distance from the antenna (see references 1 and 2). Traditional spherical coordinates consist of a radial distance, an elevation angle, and an azimuthal angle as shown in Figure 1. The elevation angle is taken as the angle between a line drawn from the origin to the point and the z axis. The azimuthal angle is taken as the angle between the projection of this line in the x-y plane and the x axis. -
Reconfigurable Reflectarrays and Array Lenses for Dynamic Antenna Beam Control: a Review 3
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. XX, NO. YY, MONTH 2013 1 Reconfigurable Reflectarrays and Array Lenses for Dynamic Antenna Beam Control: A Review Sean Victor Hum, Senior Member, IEEE, and Julien Perruisseau-Carrier, Senior Member, IEEE Abstract—Advances in reflectarrays and array lenses with gain antenna alternatives. Recently, researchers have become electronic beam-forming capabilities are enabling a host of new interested in electronically tunable versions of reflectarrays possibilities for these high-performance, low-cost antenna archi- and array lenses to realize reconfigurable beam-forming. By tectures. This paper reviews enabling technologies and topologies of reconfigurable reflectarray and array lens designs, and surveys making the scatterers in the aperture electronically tunable a range of experimental implementations and achievements that through the introduction of discrete elements such as varactor have been made in this area in recent years. The paper describes diodes, PIN diode switches, ferro-electric devices, and MEMS the fundamental design approaches employed in realizing recon- switches within the scatterer, the surface as a whole can be figurable designs, and explores advanced capabilities of these electronically shaped to adaptively synthesize a large range of nascent architectures, such as multi-band operation, polarization manipulation, frequency agility, and amplification. Finally, the antenna patterns. At high frequencies, tunable electromagnetic paper concludes by discussing future challenges and possibilities materials such as ferro-electric films, liquid crystals, and even for these antennas. new materials such as graphene can be used to as part of Index Terms—Reconfigurable antennas, reflectarrays, reflector the construction of the reflectarray elements to achieve the antennas, array lenses, transmitarrays, lens antennas, antenna ar- same effect. -
A Near Field Propagation Law & a Novel Fundamental Limit To
Preprint – Submitted to IEEE APS Conference July 2005; © 2005 Dr. Hans Schantz A Near Field Propagation Law & A Novel Fundamental Limit to Antenna Gain Versus Size Hans Gregory Schantz ([email protected]) The Q-Track Corporation; 515 Sparkman Drive; Huntsville, AL 35816 ABSTRACT This paper presents a theoretical analysis of the near field channel in free space. Then this paper validates the theoretical model by comparison to data measured in an open field. The results of this paper are important for low frequency RF systems, such as those operating at short range in the AM broadcast band. Finally this paper establishes a novel fundamental limit for antenna gain versus size. 1. INTRODUCTION The “leading edge” of RF practice moves to increasingly higher and higher frequency in lock step with advances in electronics technology. The most commercially significant RF systems are those operating at microwave frequencies and above, such as cellular telephones and wireless data networks. Microwave frequencies have the advantage of short wavelengths, making antenna design relatively straightforward, and vast expanses of spectrum, making large bandwidth, high data rate transmissions possible. There are many applications, however, that do not require large bandwidths. These include real time locating systems (RTLS) and low data rate communications systems, such as hands free wireless mikes or other voice or low data rate telemetry links. For applications like these, lower frequencies have great utility. Lower frequencies tend to be more penetrating than higher frequencies. Lower frequencies tend to diffract around objects that would block higher frequencies. Lower frequencies are less prone to multipath. -
Wireless Systems Guide for ANTENNA SETUP
A Shure Educational Publication WIRELESS SYSTEMS GUIDE ANTENNA SETUP By Gino Sigismondi and Crispin Tapia Wireless Systems Guide for Table of Contents ANTENNA SETUP Introduction . 4 Section Two . 12 Section One . 5 Diagrams . 12 2 receivers. 12 Antenna Types . 5 3-4 receivers . 12 Omnidirectional Antennas . 5 5-8 receivers . 12 Unidirectional Antennas. 5 9-12 receivers . 13 13-16 receivers . 13 Antenna Placement . 6 Large system: 50 channels . 13 Antenna Spacing . 6 Antenna Height . 7 Antenna combining: Antenna Orientation . 7 2-4 systems . 14 5-8 systems . 14 Antenna Distribution . 7 9-12 systems . 15 Passive Splitters (2 receivers). 7 13-16 systems. 15 Active Antenna Distribution (3 or more receivers) . 8 Remote antenna: 100 feet (˜30 m) . 16 Antenna Remoting . 8 75 feet (˜20 m) . 16 50 feet (˜15 m) . 16 Antenna Combining . 10 30 feet (˜10 m) . 17 Multi-room Antenna Setups. 10 <30 feet (˜10 m) . 17 Antenna Combining for Personal Monitor Transmitters. 10 About the Authors . 18 Quick Tips . 11 Suggested Reading . 11 Antenna Setup 3 Wireless Systems Guide for ANTENNA SETUP Introduction The world of professional audio is filled with considerations such as antenna size, orientation, transducers. A transducer is a device that converts and proper cable selection, are important one form of energy to another. In the case of factors not to be overlooked. Without getting too microphones and loudspeakers, sound waves are technical, this guide presents a series of good converted to electrical impulses, and vice versa. practices for most typical wireless audio The proliferation of wireless audio systems has applications. Note that these recommendations introduced yet another category of transducer to only apply to professional wireless systems with professional audio, the antenna.