Phased Array Antenna Element Evaluation Jacob Samuelsson
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
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. -
Array Designs for Long-Distance Wireless Power Transmission: State
INVITED PAPER Array Designs for Long-Distance Wireless Power Transmission: State-of-the-Art and Innovative Solutions A review of long-range WPT array techniques is provided with recent advances and future trends. Design techniques for transmitting antennas are developed for optimized array architectures, and synthesis issues of rectenna arrays are detailed with examples and discussions. By Andrea Massa, Member IEEE, Giacomo Oliveri, Member IEEE, Federico Viani, Member IEEE,andPaoloRocca,Member IEEE ABSTRACT | The concept of long-range wireless power trans- the state of the art for long-range wireless power transmis- mission (WPT) has been formulated shortly after the invention sion, highlighting the latest advances and innovative solutions of high power microwave amplifiers. The promise of WPT, as well as envisaging possible future trends of the research in energy transfer over large distances without the need to deploy this area. a wired electrical network, led to the development of landmark successful experiments, and provided the incentive for further KEYWORDS | Array antennas; solar power satellites; wireless research to increase the performances, efficiency, and robust- power transmission (WPT) ness of these technological solutions. In this framework, the key-role and challenges in designing transmitting and receiving antenna arrays able to guarantee high-efficiency power trans- I. INTRODUCTION fer and cost-effective deployment for the WPT system has been Long-range wireless power transmission (WPT) systems soon acknowledged. Nevertheless, owing to its intrinsic com- working in the radio-frequency (RF) range [1]–[5] are plexity, the design of WPT arrays is still an open research field currently gathering a considerable interest (Fig. -
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. -
1- Consider an Array of Six Elements with Element Spacing D = 3Λ/8. A
1- Consider an array of six elements with element spacing d = 3 λ/8. a) Assuming all elements are driven uniformly (same phase and amplitude), calculate the null beamwidth. b) If the direction of maximum radiation is desired to be at 30 o from the array broadside direction, specify the phase distribution. c) Specify the phase distribution for achieving an end-fire radiation and calculate the null beamwidth in this case. 5- Four isotropic sources are placed along the z-axis as shown below. Assuming that the amplitudes of elements #1 and #2 are +1, and the amplitudes of #3 and #4 are -1, find: a) the array factor in simplified form b) the nulls when d = λ 2 . a) b) 1- Give the array factor for the following identical isotropic antennas with N and d. 3- Design a 7-element array along the x-axis. Specifically, determine the interelement phase shift α and the element center-to-center spacing d to point the main beam at θ =25 ° , φ =10 ° and provide the widest possible beamwidth. Ψ=x kdsincosθφα +⇒= 0 kd sin25cos10 ° °+⇒=− αα 0.4162 kd nulls at 7Ψ nnπ2 nn π 2 =±, = 1,2, ⋅⋅⋅⇒Ψnull =±7 , = 1,2,3,4,5,6 α kd2π n kd d λ α −=−7 ( =⇒= 1) 0.634 ⇒= 0.1 ⇒=− 0.264 2- Two-element uniform array of isotropic sources, positioned along the z-axis λ 4 apart is seen in the figure below. Give the array factor for this array. Find the interelement phase shift, α , so that the maximum of the array factor occurs along θ =0 ° (end-fire array). -
Antenna Arrays
ANTENNA ARRAYS Antennas with a given radiation pattern may be arranged in a pattern line, circle, plane, etc.) to yield a different radiation pattern. Antenna array - a configuration of multiple antennas (elements) arranged to achieve a given radiation pattern. Simple antennas can be combined to achieve desired directional effects. Individual antennas are called elements and the combination is an array Types of Arrays 1. Linear array - antenna elements arranged along a straight line. 2. Circular array - antenna elements arranged around a circular ring. 3. Planar array - antenna elements arranged over some planar surface (example - rectangular array). 4. Conformal array - antenna elements arranged to conform two some non-planar surface (such as an aircraft skin). Design Principles of Arrays There are several array design var iables which can be changed to achieve the overall array pattern design. Array Design Variables 1. General array shape (linear, circular,planar) 2. Element spacing. 3. Element excitation amplitude. 4. Element excitation phase. 5. Patterns of array elements. Types of Arrays: • Broadside: maximum radiation at right angles to main axis of antenna • End-fire: maximum radiation along the main axis of ant enna • Phased: all elements connected to source • Parasitic: some elements not connected to source: They re-radiate power from other elements. Yagi-Uda Array • Often called Yagi array • Parasitic, end-fire, unidirectional • One driven element: dipole or folded dipole • One reflector behind driven element and slightly longer -
Army Phased Array RADAR Overview MPAR Symposium II 17-19 November 2009 National Weather Center, Oklahoma University, Norman, OK
UNCLASSIFIED Presented by: Larry Bovino Senior Engineer RADAR and Combat ID Division Army Phased Array RADAR Overview MPAR Symposium II 17-19 November 2009 National Weather Center, Oklahoma University, Norman, OK UNCLASSIFIED UNCLASSIFIED THE OVERALL CLASSIFICATION OF THIS BRIEFING IS UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED RADAR at CERDEC § Ground Based § Counterfire § Air Surveillance § Ground Surveillance § Force Protection § Airborne § SAR § GMTI/AMTI UNCLASSIFIED UNCLASSIFIED RADAR Technology at CERDEC § Phased Arrays § Digital Arrays § Data Exploitation § Advanced Signal Processing (e.g. STAP, MIMO) § Advanced Signal Processors § VHF to THz UNCLASSIFIED UNCLASSIFIED Design Drivers and Constraints § Requirements § Operational Needs flow down to System Specifications § Platform or Mobility/Transportability § Size, Weight and Power (SWaP) § Reliability/Maintainability § Modularity, Minimize Single Point Failures § Cost/Affordability § Unit and Life Cycle UNCLASSIFIED UNCLASSIFIED RADAR Antenna Technology at Army Research Laboratory § Computational electromagnetics § In-situ antenna design & analysis § Application Examples: § Body worn antennas § Rotman lens § Wafer level antenna § Phased arrays with integrated MEMS devices § Collision avoidance radar § Metamaterials UNCLASSIFIED UNCLASSIFIED Antenna Modeling § CEM “Toolkit” requires expert users § EM Picasso (MoM 2.5D) – modeling of planar antennas (e.g., patch arrays) § XFDTD (FDTD) – broadband modeling of 3-D structures (e.g., spiral) § HFSS (FEM) – modeling of 3-D structures (e.g., -
Agile 3-D Beam-Steering for 60 Ghz Wireless Networks Anfu Zhou∗, Leilei Wu∗, Shaoqing Xu∗, Huadong Ma∗, Teng Wei†, Xinyu Zhang‡ ∗ Beijing Key Lab of Intell
Following the Shadow: Agile 3-D Beam-Steering for 60 GHz Wireless Networks Anfu Zhou∗, Leilei Wu∗, Shaoqing Xu∗, Huadong Ma∗, Teng Weiy, Xinyu Zhangz ∗ Beijing Key Lab of Intell. Telecomm. Software and Multimedia, Beijing University of Posts and Telecomm. y Department of Electrical and Computer Engineering, University of Wisconsin-Madison z Department of Electrical and Computer Engineering, University of California San Diego Email: fzhouanfu,layla,donggua,[email protected], [email protected], [email protected] Abstract—60 GHz networks, with multi-Gbps bitrate, are Much effort has been devoted to design agile beam-steering, considered as the enabling technology for emerging applications from the hierarchical beam scanning defined in standards [1], such as wireless Virtual Reality (VR) and 4K/8K real-time [9], to heuristic-based shortcuts [10], [11] or sensing-inspired Miracast. However, user motion, and even orientation change, can cause mis-alignment between 60 GHz transceivers’ directional solutions [12], [13]. However, these methods mainly focus on beams, thus causing severe link outage. Within the practical 3D two dimensional (2D) beam-steering, e.g., assuming a phased- spaces, the combination of location and orientation dynamics array that can steer the main beam among different angles leads to exponential growth of beam searching complexity, which within a 2D plane. In practice, the users and radios move in 3D substantially exacerbates the outage and hinders fast recovery. space; and a 60 GHz array can comprise a planar “matrix” of In this paper, we first conduct an extensive measurement to analyze the impact of 3D motion on 60 GHz link performance, antenna elements, steering the beams towards different angles in the context of VR and Miracast applications. -
Introduction
c01.qxd 12/1/2005 3:06 PM Page 1 1 INTRODUCTION 1.1 THE DEFINITION OF A CONFORMAL ANTENNA A conformal antenna is an antenna that conforms to something; in our case, it conforms to a prescribed shape. The shape can be some part of an airplane, high-speed train, or other vehicle. The purpose is to build the antenna so that it becomes integrated with the struc- ture and does not cause extra drag. The purpose can also be that the antenna integration makes the antenna less disturbing, less visible to the human eye; for instance, in an urban environment. A typical additional requirement in modern defense systems is that the an- tenna not backscatter microwave radiation when illuminated by, for example, an enemy radar transmitter (i.e., it has stealth properties). The IEEE Standard Definition of Terms for Antennas (IEEE Std 145-1993) gives the following definition: 2.74 conformal antenna [conformal array]. An antenna [an array] that conforms to a sur- face whose shape is determined by considerations other than electromagnetic; for example, aerodynamic or hydrodynamic. 2.75 conformal array. See: conformal antenna. Strictly speaking, the definition includes also planar arrays if the planar “shape is deter- mined by considerations other than electromagnetic.” This is, however, not common practice. Usually, a conformal antenna is cylindrical, spherical, or some other shape, with the radiating elements mounted on or integrated into the smoothly curved surface. Many Conformal Array Antenna Theory and Design. By Lars Josefsson and Patrik Persson 1 © 2006 Institute of Electrical and Electronics Engineers, Inc. c01.qxd 12/1/2005 3:06 PM Page 2 2 INTRODUCTION variations exist, though, like approximating the smooth surface by several planar facets. -
Integrated Optical Phased Arrays for Beam Forming and Steering
applied sciences Review Integrated Optical Phased Arrays for Beam Forming and Steering Yongjun Guo 1,2, Yuhao Guo 1,2, Chunshu Li 1,2, Hao Zhang 1,2, Xiaoyan Zhou 1,2 and Lin Zhang 1,2,* 1 Key Laboratory of Opto-Electronics Information Technology of Ministry of Education, School of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China; [email protected] (Y.G.); [email protected] (Y.G.); [email protected] (C.L.); [email protected] (H.Z.); [email protected] (X.Z.) 2 Key Laboratory of Integrated Opto-Electronic Technologies and Devices in Tianjin, School of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China * Correspondence: [email protected] Abstract: Integrated optical phased arrays can be used for beam shaping and steering with a small footprint, lightweight, high mechanical stability, low price, and high-yield, benefiting from the mature CMOS-compatible fabrication. This paper reviews the development of integrated optical phased arrays in recent years. The principles, building blocks, and configurations of integrated optical phased arrays for beam forming and steering are presented. Various material platforms can be used to build integrated optical phased arrays, e.g., silicon photonics platforms, III/V platforms, and III–V/silicon hybrid platforms. Integrated optical phased arrays can be implemented in the visible, near-infrared, and mid-infrared spectral ranges. The main performance parameters, such as field of view, beamwidth, sidelobe suppression, modulation speed, power consumption, scalability, and so on, are discussed in detail. Some of the typical applications of integrated optical phased arrays, such as free-space communication, light detection and ranging, imaging, and biological sensing, are shown, with future perspectives provided at the end. -
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.