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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. -
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., -
April 19, 2016
Vol. 64, No. 4 – April 2016 GENERAL MEETING THE PRESIDIO . OBSERVATION POST . BUILDING 211 211 Lincoln Boulevard, San Francisco 7:00 pm Doors Open . 7:30 pm Announcements . 8:00 pm Speaker !!! APRIL GENERAL MEETING !!! !!! DIFFERENT LOCATION FOR APRIL GENERAL MEETING ONLY !!! GENERAL MEETING WILL BE AT PRESIDIO OFFICERS’ CLUB SEE NEXT PAGE FOR DIRECTIONS April 19, 2016 DR. MARK MARLEY THE NEW ERA OF EXOPLANET DISCOVERY Although science fiction has long dreamed of their existence, it has only been 20 years since the announcement of the first confirmed extrasolar planets. We now know of thousands of worlds beyond our own solar system. Almost all of these planets were discovered by indirect means, mostly by searches for the subtle effects of these distant planets on their own suns. While astronomers have developed astounding methods for teasing out details about many of these planets, the vast majority will forever remain as little more than curves and dips on data plots. However as we enter the third decade of exoplanet science a new method of discovery is coming to the forefront: direct imaging. This method aims to block the light of stars so that the planets that orbit them can be directly detected. Directly imaged planets are not only somehow more satisfying, they also offer many more opportunities for in depth study since their light is naturally separated from that of their star. In my talk I will explain how direct imaging is already helping us to understand the origin and evolution of giant planets around young stars and I will discuss the promise this method holds in the search for life on Earth-like planets in the future. -
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. -
Light Pollution from Satellites
CENTER FOR SPACE POLICY AND STRATEGY SPACE AGENDA 2021 LIGHT POLLUTION FROM SATELLITES Josef S. Koller, Roger C. Thompson, and Luc H. Riesbeck Commercial space companies, such as SpaceX, Telesat, OneWeb, and Amazon, have announced plans to launch large constellations of small satellites into low Earth orbit (LEO). As companies deploy more satellites in orbit in much larger numbers than in previous decades, this will become an issue in the next several years that requires leadership and decisionmaking by the U.S. administration—because there is currently no formal regulatory or licensing process addressing light pollution from space. The purpose of this paper is to provide an overview of an objective analysis performed by The Aerospace Corporation to inform leaders and decisionmakers on the issue.1 Background The logic behind the large constellation architecture is to take advantage of advancements in automation and miniaturization achieved in the past two decades to quickly build and operate several thousand satellites. These “smallsats” are comparatively inexpensive, faster to produce, and can be more readily replaced and upgraded. Should they all achieve orbit, the proposed commercial large-constellation satellites launched could total well over 17,000, distributed primarily between low and very low Earth orbits by the end of the 2020s2 and could surpass 50,000 in the following decade.3 The scale of these planned constellations combined is more than twenty times the current satellite population in orbit.* Despite the potential benefits from the proposed proliferated LEO (pLEO) constellations (sometimes referred to colloquially as mega-constellations) and the recent public discussion on this topic, the aggregate effects of light pollution from such constellations remain underexamined in an objective way. -
Exploring the Capabilities of Phased Array Antennas A
UNIVERSITY OF CALIFORNIA, SAN DIEGO Antarctica: Exploring the Capabilities of Phased Array Antennas A thesis submitted in partial satisfaction of the requirements for the degree Master of Science in Computer Science by Shaan Suresh Mahbubani Committee in charge: Professor Alex C. Snoeren, Chair Professor Stefan Savage Professor Geoffrey M. Voelker 2008 Copyright Shaan Suresh Mahbubani, 2008 All rights reserved. The Thesis of Shaan Suresh Mahbubani is approved and it is acceptable in quality and form for publication on microfilm: Chair University of California, San Diego 2008 iii DEDICATION If you can dream{and not make dreams your master, If you can think{and not make thoughts your aim; If you can meet with Triumph and Disaster And treat those two impostors just the same; If you can bear to hear the truth you've spoken Twisted by knaves to make a trap for fools, Or watch the things you gave your life to, broken, And stoop and build `em up with worn-out tools: If you can fill the unforgiving minute With sixty seconds' worth of distance run, Yours is the Earth and everything that's in it, And{which is more{you'll be a Man, my son! {Rudyard Kipling iv TABLE OF CONTENTS Signature Page . iii Dedication . iv Table of Contents . v List of Figures . vii List of Tables . ix Acknowledgements . x Abstract of the Thesis . xi 1 Introduction . 1 1.1 Focus of the thesis . 5 1.2 Overview of the thesis . 6 2 Background and Related Work . 7 2.1 Background . 8 2.1.1 Wireless networking . -
Wideband Phased Array & Rectenna Design And
WIDEBAND PHASED ARRAY & RECTENNA DESIGN AND MODELING FOR WIRELESS POWER TRANSMISSION A Dissertation by JONATHAN NOEL HANSEN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2011 Major Subject: Electrical Engineering Wideband Phased Array & Rectenna Design and Modeling for Wireless Power Transmission Copyright 2011 Jonathan Noel Hansen WIDEBAND PHASED ARRAY & RECTENNA DESIGN AND MODELING FOR WIRELESS POWER TRANSMISSION A Dissertation by JONATHAN NOEL HANSEN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Kai Chang Committee Members, Krzysztof Michalski Laszlo Kish Kenith Meissner Head of Department, Costas Georghiades December 2011 Major Subject: Electrical Engineering iii ABSTRACT Wideband Phased Array & Rectenna Design and Modeling for Wireless Power Transmission. (December 2011) Jonathan Noel Hansen, B.S., Texas A&M University Chair of Advisory Committee: Dr. Kai Chang Microstrip patch antennas are the most common type of printed antenna due to a myriad of advantages which encourage use in a wide range of applications such as: wireless communication, radar, satellites, remote sensing, and biomedicine. An initial design for a stacked-patch, broadband, dual-polarized, aperture-fed antenna is tested, and some adjustments are made to improve performance. The design goal is to obtain a 3 GHz bandwidth centered at 10 GHz for each polarization. Once the single-element design is finalized, it is used in a 4x1 array configuration. An array increases the gain, and by utilizing variable phase-shifters to each element, the pattern can be electronically steered in a desired direction. -
CALIFORNIA STATE UNIVERSITY, NORTHRIDGE Frequency
CALIFORNIA STATE UNIVERSITY, NORTHRIDGE Frequency Modulated Continuous Wave Radar Design and Simulation A graduate project submitted in partial fulfillment of the requirements For the degree of Master of Science in Electrical Engineering By Mark Christopher Fessia December 2018 The graduate project of Mark Christopher Fessia is approved: _____________________________________ __________________ Dr. Ali Amini Date _____________________________________ __________________ Mr. James A. Flynn Date _____________________________________ __________________ Dr. Deborah K. Van Alphen, Chair Date California State University, Northridge ii Table of Contents Signature Page ii List of Tables iv List of Figures v Abstract vi Section 1: Objective 1 Section 2: Introduction 3 Section 3: Literature Review 11 Section 4: Analysis and Design 13 Section 5: Implementation 31 Section 6: Testing and Results 57 Conclusion 65 References 67 Appendix A: MATLAB Source Code 69 iii List of Tables Table Number Caption Page 4.1 Modulator Simulation Parameters 15 4.2 Voltage Controlled Oscillator Simulation Parameters 17 4.4 Low Noise Amplifier Simulation Parameters 20 4.6 Antenna Simulation Parameters 23 4.9.1 Simulation Parameters for Radar Equation 27 4.9.2 Simulation Parameters for Maximum Range Calculation 29 5.2.1 phased.FMCWWaveform Parameters 33 5.2.2 comm.PhaseNoise Parameters 34 5.4 phased.ReceiverPreamp Parameters 37 5.6.1 phased.CustomAntennaElement Parameters 40 5.6.2 phased.Transmitter Parameters 41 5.6.3 phased.Radiator Parameters 42 5.6.4 phased.Collector Parameters 43 5.8.1 Low Pass Filter Specifications 45 5.9.1 phased.FreeSpace Parameters 49 5.9.2 phased.RadarTarget Parameters 50 6.1 Theoretical vs. Measured Signal Power 57 6.2 Target Range Calculation Parameters 59 6.3 Moving Target, Velocity and Range Calculation Parameters 62 7.1 Range and Velocity Measurement Errors 65 iv List of Figures Figure Number Description Page 2.1 Architecture of CW radar. -
Laboratory Instruction in Undergraduate Astronautics
Session 2302 Laboratory Instruction in Undergraduate Astronautics Christopher D. Hall Aerospace and Ocean Engineering Virginia Polytechnic Institute and State University Introduction One significant distinction between the “standard” educational programs in aeronautical and astro- nautical engineering is the extent to which experimental methods are incorporated into the curricu- lum. The use of wind tunnels and their many variations is firmly established in the aeronautical engineering curricula throughout the United States. In astronautical engineering, however, there do not appear to be any standard experimental facilities in wide use. This is understandable, given the unique environment in which spacecraft operate; however, there are several facilities which could fill this role, some of which are already in place at universities with a strong space emphasis. The purpose of this paper is to describe some of these facilities and their uses in teaching undergraduate astronautics. We begin by describing the topics in astronautics that are distinct from other topics in aerospace engineering. We then describe a variety of field exercises and laboratories that can be used to enrich the teaching of astronautics. These exercises focus on satellite “observation,” both visually and using amateur radio receivers. Additional laboratories described include a Spacecraft Attitude Dynamics and Control Simulator, and a “design, build, and fly” project to be launched in late 2001. Topics in Astronautics Some topics in aerospace engineering, such as structures, are common to both aeronautics and astronautics, so that related laboratories benefit both parts of the curriculum. There are however some space-specific topics that typically have no laboratory component, primarily related to the motion of spacecraft. -
Realization of a Planar Low-Profile Broadband Phased Array Antenna
REALIZATION OF A PLANAR LOW-PROFILE BROADBAND PHASED ARRAY ANTENNA DISSERTATION Presented in Partial Ful¯llment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Justin A. Kasemodel, M.S., B.S. Graduate Program in Electrical and Computer Engineering The Ohio State University 2010 Dissertation Committee: John L.Volakis, Co-Adviser Chi-Chih Chen, Co-Adviser Joel T. Johnson ABSTRACT With space at a premium, there is strong interest to develop a single ultra wide- band (UWB) conformal phased array aperture capable of supporting communications, electronic warfare and radar functions. However, typical wideband designs transform into narrowband or multiband apertures when placed over a ground plane. There- fore, it is not surprising that considerable attention has been devoted to electromag- netic bandgap (EBG) surfaces to mitigate the ground plane's destructive interference. However, EBGs and other periodic ground planes are narrowband and not suited for wideband applications. As a result, developing low-cost planar phased array aper- tures, which are concurrently broadband and low-pro¯le over a ground plane, remains a challenge. The array design presented herein is based on the in¯nite current sheet array (CSA) concept and uses tightly coupled dipole elements for wideband conformal op- eration. An important aspect of tightly coupled dipole arrays (TCDAs) is the capac- itive coupling that enables the following: (1) allows ¯eld propagation to neighboring elements, (2) reduces dipole resonant frequency, (3) cancels ground plane inductance, yielding a low-pro¯le, ultra wideband phased array aperture without using lossy ma- terials or EBGs on the ground plane.