About the Webinar
 

The Antenna Measurement Techniques Association cordially invites you to spend time with top experts presenting the most recent developments in the industry. The agenda offers a FREE, half day of presentations and interactive discussion in a LIVE Webinar on Thursday, April 22, 2021. 
 

Schedule
 

Thursday, April 22 2021
 

Time (PDT)

Presenter

Organization

Presentation Title

07:55

Stuart Gregson & Justin Dobbins

NPM, QMUL

Raytheon Technologies

Welcome & Announcements

08:00

Jonathan D. Lawrence

Ryan T. Cutshall

Raytheon Technologies

Simulating Near Field Measurement Errors for
Spherical & Planar Geometries

08:30

Lars Jacob Foged

MVG

Investigation of Probe (Im)perfection vs Measurement Accuracy
in Spherical Near-Field Systems

09:00

Marion C. Baggett

NSI-MI Technologies LLC.

The Cost of Accuracy

09:30

Break

09:45

Jacob Freking

Raytheon Technologies

Simulation of Test Zone Scattering in a
RCS Compact Range

10:15

C.J. Reddy

Altair Engineering, Inc.

Simulation of Antenna Measurements Using
Advanced Computational Techniques

10:45

Bharath Kashyap

George Trichopoulos

Arizona State University

Radar Cross Section Characterization of a 220 GHz
Reconfigurable Reflective Surface

11:15

Stuart Gregson & Justin Dobbins

NPM, QMUL

Raytheon Technologies

Final Q&A, Discussion & Close.


Session Details
 

Simulating Near Field Measurement Errors for Spherical & Planar Geometries
Jonathan D. Lawrence & Ryan T. Cutshall
 

Abstract: Planar near-field and spherical near-field measurement simulators can provide insight into how various error sources (noise, drift, scattering, etc.) impact the uncertainty of the far-field pattern recovered via standard near-field to far-field transformation algorithms. We will discuss the creation and use of a planar near-field simulation tool (pnfSim) and a spherical near-field simulation tool (SNF SIM), and demonstrate how measured error sources can be used to support “one-at-a-time” or “all-errors-at-once” uncertainty evaluations.

Bio: Jonathan D. Lawrence received his Ph.D. in experimental condensed matter physics, specializing in electron spin resonance spectroscopy, from the University of Florida in 2007.  After spending 1 year as a teaching faculty member at the University of Arizona, he joined Raytheon Missiles and Defense in 2009.  Since then his work at Raytheon has been focused primarily on antenna & radome calibration in spherical near field antenna measurement facilities.

Bio: Ryan T. Cutshall received his B.S. degree in engineering mechanics from the University of Wisconsin – Madison in 2008, and his M.S. degree in electrical engineering from the University of Arizona in 2013. He is currently employed at Raytheon Missiles and Defense, a division of Raytheon Technologies, working in the RF Products department. His work at Raytheon Technologies is primarily focused on antenna design and measurement. He has been a member of the Antenna Measurement Techniques Association since 2013.


Investigation of Probe (Im)perfection vs Measurement Accuracy in Spherical Near-Field Systems
Lars Jacob Foged
 

Abstract: The transmission formula is a very powerful tool which is normally used to apply first and higher order probe compensation in Spherical Near Field (SNF) measurements. It allows the computation of the coupling between a transmitting and a receiving antenna, hence it can actually be exploited for many purposes, including the emulation of measurement scenarios.

Bio: Lars Jacob Foged received his M.S. in Electrical Engineering from California Institute of Technology, USA in 1990. He is Scientific Director of the Microwave Vision Group.  He was member of the EURAAP Delegate Assembly and responsible for the Working Group on Antenna Measurements from 2009 to 2012. At EUCAP conferences, he was Vice-Chair in 2011 and 2022, Industrial Chair in 2012, 2014, 2017, and Technical Program Chair in 2016 and 2021. Since 2004, he was secretary and now vice-chair of the IEEE Antenna Standards Committee. In 2016 and 2017, he led the Industry Initiatives Committee (IIC) of IEEE APS. He is board member and course organizer in the European School of Antennas (ESOA) since 2006. He is Board Member, Fellow and Distinguished Achievement Award recipient of AMTA. He has authored or co-authored more than 300 journal and conference papers on antenna design and measurement topics and received the “Best Technical Paper Award” at the 2012 AMTA symposium. He contributed to six books and standards, and hold four patents.


The Cost of Accuracy
Marion Baggett
 

Abstract: The accuracy needed for a measurement campaign is dependent on many factors.  One factor is the stage of the AUT life cycle (initial qualification of a design, production or repair) that is making the measurements. The affordability of the accuracy in terms of more costly equipment, calibration processes and operator and test range time is also a constraint.  Throughput needs in a production environment may limit the accuracy that can be obtained.  The specifications on the test article directly affect the required measurement accuracy.  The metrics and the accuracies required for each metric must then be evaluated against the accuracy of an available test range or ranges or the renovation of an existing range or construction of a new range to meet the accuracy requirements.  This presentation will discuss the various constraining factors in accuracy requirements and present several case studies.  These case studies will include: Approaches to improving gain accuracy, Improvement of the positioning accuracy of a rotator via custom hardware and calibration for a severe global positioning accuracy specification, Quick near-field data collection to meet a throughput requirement, Approaches to increasing side lobe measurement accuracy.

Bio: Marion C. Baggett is an Applications and Systems Engineer at NSI-MI Technologies, LLC. This group includes engineers responsible for customer applications development and systems engineering. Marion has been in this position since May 2014. He came to NSI-MI as the Manager of Software Engineering in April 2002 from a similar position at ViaSat, Inc. He became Manager of Applications and Systems Engineering in 2007 and served in that capacity through 2013. NSI-MI was formed by the merger of NSI and MI Technologies in January of 2016.  During previous service at Scientific-Atlanta, Marion spent ten years with the Microwave and Radar Cross-Section Instrumentation products from 1984 through 1994. Marion’s engineering and management career includes twenty years with Scientific-Atlanta and ViaSat, Inc. in the tracking systems, microwave instrumentation, radar cross-section and satellite gateway product lines. From 1982 through 2000, Marion held various staff engineer and management positions at Scientific-Atlanta, including participating in the founding of the radar cross-section product group in 1984. Among his assignments were Manager of RCS Software Engineering, Staff Engineer in Microwave Products and Staff Engineer in Satellite Ground Systems and finally a Principal Engineer for the company. During the period from 1994 through 2000, Marion was initially the lead software engineer and later project engineer for the Iridium™ Earth Terminals. In 2000, ViaSat, Inc. purchased the Satellite Ground Systems group from Scientific-Atlanta. At ViaSat, Marion was Manager of Satellite Ground System Software Engineering.  Marion is an Edmond S. Gillespie Fellow of the Antenna Measurement Techniques Association (AMTA), a Senior Member of IEEE and is also a registered Professional Engineer. Marion was a member of the AMTA student paper evaluation committee for 11 years. He has authored or co-authored 19 technical publications in the areas of microwave measurements.  Marion holds a Bachelor of Electrical Engineering Degree and Master of Science in Electrical Engineering Degree from the Georgia Institute of Technology. He also holds a Master of Science in Engineering Management from the University of Alabama in Huntsville.


Simulation of Test Zone Scattering in a RCS Compact Range
Jacob Freking
 

Abstract: A tower and foam columns are needed to support targets in a RCS compact test range because some targets cannot be mounted on pylons. The height of the foam column is driven by fabrication and mechanical limitations. A wall of Radar Absorbing Material (RAM) was introduced to reduce the impact of the foam column support tower on measurements. The RAM wall effectively shadows the tower and base of column, but creates unacceptable edge diffraction in the compact range quiet zone. We need to preserve the quiet zone performance relative to the case without the RAM wall present. We developed a streamlined simulation workflow involving TICRA GRASP’s physical optics solver, Dassault Systemes’ CST’s finite difference time domain simulation with near-field sources, and plane wave spectrum (PWS) projection in MATLAB to evaluate the RAM wall’s effect on the quiet zone. A figure of merit based on statistical analysis of the results was also developed to provide quick design decisions based on simulated results.

Bio: Jacob Freking is an antenna engineer at Raytheon Missile and Defense in Tucson, AZ. He has a BS in electrical engineering from Texas A&M University and is pursuing a MS in electrical engineering at Arizona State University. His work focuses on antenna measurements, specifically in near-field antenna ranges.


Simulation of Antenna Measurements Using Advanced Computational Techniques
CJ Ready
 

Abstract: Recent advances in Computational electromagnetic (CEM) simulations made them possible to be a cost-effective solution for designing and characterizing antenna measurement facilities. Using both full wave and asymptotic techniques, it is possible to characterize the performance of large measurement facilities such as anechoic chambers and compact antenna test ranges (CATR) with large parabolic reflectors. The measurement community has a substantial and increasing interest in utilizing computational electromagnetic (CEM) tools to minimize the financial and real estate resources required to design and construct a custom anechoic chamber without sacrificing performance. In this talk, the use of full wave techniques such as Finite Element Method (FEM) and Multilevel Fast Multipole Method (MLFMM) as well as asymptotic techniques such as Physical Optics (PO) and Ray-Launching Geometrical Optics (RL-GO) for quiet zone characterizations as well as emulation of antenna measurements in both anechoic chambers as well as CATRs will be presented.

Bio: Dr. C.J. Reddy is Vice President, Business Development-Electromagnetics for Americas at Altair Engineering, Inc. (www.altair.com). Dr. Reddy received his B.Tech. degree in Electronics and Communication Engineering (ECE) from Regional Engineering College, Warangal, India, M.Tech. and Ph.D. degrees in Electrical Engineering from Indian Institute of Technology, Kharagpur, India. He worked as Scientific Officer at SAMEER (Society for Microwave Electronics Engineering and Research), Mumbai during 1987-1991. Dr. Reddy was awarded the Natural Sciences and Engineering Research Council (NSERC) of Canada Visiting Fellowship to work at Communications Research Center in Ottawa during 1991-1993 and was awarded the US National Research Council (NRC) Resident Research Associateship in 1993 to work at NASA Langley Research Center in Hampton, Virginia. While conducting research at NASA Langley, he developed various computational codes for electromagnetics and received a Certificate of Recognition from NASA for development of a hybrid Finite Element Method/Method of Moments/Geometrical Theory of Diffraction code for cavity backed aperture antenna analysis. He also worked as Research Professor at Hampton University from 1995 to 2000. Dr. Reddy was the President of Applied EM, Inc (2000-2017) where he led several Phase I and Phase II SBIR projects for the DoD and NASA. He was also the President of EM Software & Systems (USA) Inc (2002-2014) and led the marketing of the EM Simulation tool, Feko in North America. EM Software & Systems (USA) Inc was acquired by Altair in 2014.  Dr. Reddy is a Fellow of IEEE, Fellow of ACES (Applied Computational Electromagnetics Society) and a Fellow of AMTA (Antenna Measurement Techniques Association). Dr. Reddy served on ACES Board of Directors from 2006 to 2012 and again from 2015 to 2018. Dr. Reddy was awarded Distinguished Alumni Professional Achievement Award by his alma mater, National Institute of Technology (NIT), Warangal, India in 2015. He published 39 journal papers, 119 conference papers and 18 NASA Technical Reports to date. Dr. Reddy is a co-author of the book, “Antenna Analysis and Design Using FEKO Electromagnetic Simulation Software,” published in June 2014 by SciTech Publishing (now part of IET). Dr. Reddy is serving as an Associate Editor for the newly introduced, IEEE Open Journal of Antennas of Propagation. He is appointed by IEEE Board of Directors to the position of IEEE Fellow Committee Member for the term 2020-2021. Dr. Reddy is elected as a member of AMTA Board of Directors for a three-year term starting Jan 2020 and is the Technical Coordinator for AMTA 2020 and AMTA 2021 Conferences.


Radar Cross Section Characterization of a 220 GHz Reconfigurable Reflective Surface
Bharath Kashyap, George Trichopoulos

Abstract: Reconfigurable reflective surfaces (RRSs) are aptly suited for future high-frequency wireless communication applications owing to their low-profile, low-RF losses, low power consumption, and high gain capabilities. RRSs can be integrated with 5G and beyond wireless communication systems to improve signal coverage by redirecting the incoming signal towards the non-line of sight users. As such, RRSs are designed to modulate the phase profile of the plane waves incident from different directions and redirect them to desired angles. The phase modulation is achieved using tunable switches (PIN diodes, graphene patches, etc.,) integrated into each unit cell of the RRS. The phases of individual elements are usually quantized using phase quantization schemes, the most prevalent being a1-bit scheme, where the phase values are rounded off to 00 or 1800. While this method offers the advantages of design simplicity and lower losses, it also leads to parasitic lobes in undesired directions due to the periodicity of the error resulting from phase rounding quantization. The only existing alternative is to employ more bits in the quantization scheme which increases the design complexities, power consumption, and losses.
In this work, we present an alternate and more robust approach to suppress such quantization lobes in single-bit RRSs, leveraging the technique of phase randomization originally introduced in phased arrays. Specifically, we introduce a random but fixed physical phase delay in each unit cell of a single-layer, 1-bit RRS to break the periodicity of the quantization errors and thereby suppress the quantization lobes. A 900-element randomized 2D- RRS has been designed at 222.5 GHz and fabricated on an alumina ribbon ceramic substrate from Corning., Inc. We have also designed and fabricated a non-randomized RRS to carry out a comparative study.

Employing a quasi-optical measurement setup, we characterize the radar cross section (RCS) of the fabricated RRS. The setup consists of two vector network analyzer (VNA) extenders, a transmitting, and a receiving horn antenna, 2 collimating lenses, and the prototype wafer, all mounted on an optical breadboard. The signal from the VNA is upconverted to 222.5 GHz using frequency extenders. The diverging beam from the transmitting horn is collimated using a Teflon lens, and the RRS is illuminated by this collimated beam. The scattered fields are measured by rotating the receiver radially covering [-200, -800] and [+200, +800], only restricted by the geometrical limitations of the setup. To ensure that there is no significant reflection in the broadside direction, the back-reflected signal is also measured. A good agreement is seen between the analytical and measured results with the RCS of the randomized RRS showing the suppression of the quantization lobe, while the non-randomized RRS contains both the main lobe as well as the undesired quantization lobe. A reduction in the quantization lobe level by about -18 dB is achieved in this work. Finally, we also characterize the bandwidth and efficiency of the designed RRS which are found to be 3.8% and 30% respectively.

Bharath G. Kashyap, Panagiotis C. Theofanopoulos, Yiran Cui, and Georgios C. Trichopoulos
School of Electrical, Computer, and Energy Engineering
Arizona State University, Tempe AZ USA 85287

Bio: Bharath received the Bachelor of Engineering degree in electronics and communication engineering from Visveswaraya Technological University, Belgaum, India, in 2014, and the Master of Science degree in electrical engineering from Arizona State University, Tempe, AZ, USA, in 2018, where he is currently pursuing the Ph.D. degree in electrical engineering. From 2018 to 2020, he was with Intel Corporation, Chandler, AZ, USA, as a Failure Analysis Research and Development Engineer. His research interests include antennas, electromagnetics, and microwave design.


More Information


For more information, and to register please enter the following in your browser: https://www.amta.org/i4a/pages/index.cfm?pageid=3491

For any questions please contact Stuart Gregson, email stuart.gregson@qmul.ac.uk


Webinar Host

 

 

To Register

This regional event webinar is FREE. To register: 

 

 


Organizing Committee
 

Stuart Gregson – AMTA Vice President
Justin Dobbins – Event Technical Coordinator & Moderator
Michelle Taylor – AMTA President
Ed Urbanik – AMTA Past Vice President
Paul DeGroot – AMTA Meeting Coordinator
Zhong Chen – AMTA Secretary


About AMTA
 

The Antenna Measurement Techniques Association (AMTA) is a non-profit professional organization for engineers and other persons active in the fields of antenna, radome, and radar cross-section measurements. The purpose of AMTA is to promote technical exchange between colleagues in these fields; provide a forum for presentations of new techniques and results in antenna and radar cross-section measurement; and offer antenna and radar cross-section measurement equipment manufacturers an opportunity to demonstrate new hardware and software to a significant portion of the market. The membership and activities of AMTA have grown in size and scope each year since the founding of the organization in 1979.

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