2010 Activities
The presentations at some meetings are available for reading and downloading on the respective linked titles.
November 22, 2010: “Antenna Measurements from Basic Concepts to Automated Systems” by Mike Hillbun, President of Diamond Engineering
Abstract: The growing necessity of measuring antennas has brought forth the need to understand antenna measurement concepts. Simple figures of merit are presented regarding propagation and polarization. Measurement considerations and test field accuracy are presented with near field, near-far, far field and multipath.
Antenna techniques for gain transfer are presented with real world examples. Finally the concept of continuous motion measurement in terms of Nyquist sampling, beam width and accuracy is presented with examples.
Reference: Practical Antenna Design, Analysis and Measurements by Dr. Yi Huang, Department of Electrical Engineering & Electronics, The University of Liverpool, Liverpool L69 3GJ
Bio: Mike Hillbun, President of Diamond Engineering. Mr Hillbun holds a Masters degree in Physics from the University of California, Berkeley . He has 30 years in experience in semiconductor and antenna design. Mr. Hillbun producted the first wireless 10MB packet radio which won first prize at Interop in 1994. Currently Diamond Engineering manufactures antenna test systems.
September 23, 2010: “Successful Applications of MoM/MLFMM to Antennas Located on Vehicles” by Keith Snyder, Sr. Member of the Technical Staff of Northrop Grumman
Abstract: Method of Moments, MoM, and Multi-Level Fast Multi-pole Method, MLFMM, are two methods for computing behavior of antennas. His talk will be about applications of the FEKO code and the successes he has had using MLFMM on Aircraft Antennas and Ground vehicles. He will show theoretical and measured results that are a breakthrough in computational speed and accuracy for Antenna Patterns, Antenna Placement, and Antenna Coupling.
Bio: Keith Snyder graduated from Ohio State University in 1980 with a BSEE degree specializing in Electromagnetics and Antennas. He worked for Harris Broadcast in Quincy Illinois matching AM transmitters to Broadcast towers using antenna matching circuits and diplexers. He used the Ohio State Numerical Codes at GTE in Needham Mass to design low sidelobe 20/30 GHz reflector Antennas. Next he worked on patch antennas and conformal antennas at Ball Aerospace in Boulder Colorado.
His career continued at Aydin Radar in San Jose California after designing several slotted planar arrays for 3D radar. GTE again requested his services in Mountain View California where he designed and patented broadband antennas for SIGINT collection systems. After 10 years of service at GTE Keith designed and tested commercial Broadcast satellite Antennas at Space Systems Loral in Palo Alto California. He is credited with putting up the first KA band spot beam antennas for Dish Network.
His current design work includes using the FEKO electromagnetic code at Northrop Grumman formerly ESL in San Jose.
April 7, 2010: “Antenna Technology for Commercial Satcom” by Michael Thorburn, Space Systems/Loral
Abstract: A variety of topics in antenna technology and antenna design methodology will be presented to give the audience an overview of this exciting field.
Bio: Dr. Michael Thorburn is Director of Engineering in the Antenna Subsystem Operation at Space Systems/Loral. Prior to accepting this role 20 months ago, he was Manager of the Communications Payload Systems Engineering Department. He is a Senior Member of the IEEE and a Senior Member of the AIAA.
March 18, 2010: “Modeling and Measurement of Dual-Circular Polarized Feed for Prime Focus Antenna” by Jeffrey Pawlan, Pawlan Communications
Abstract: Septum polarizers in antenna feeds have been used in military, and commercial satellite antennas for 45 years because of their elegant simplicity and excellent performance. However, their design is mathematically difficult. With advances in 3D field simulation software we can accurately model and optimize it for a specific application. This talk will present the history, how it works, and will show in detail how one may utilize software to not only model the feed, but also model the combination of the feed with a large reflector. The effects of the reflected signals from the center of the dish back into the feed will be shown.
Here are two audio recordings of actual signals heard reflected off of the moon on 1296MHz. The first is a CW (morse code) signal from an amateur operator in Danmark and the second is a voice communication using SSB between a Dutch operator and an E Coast operator.
CW recording
Voice recording
Bio: JEFFREY PAWLAN (M 1989, SM 1996) has been a consultant as owner of Pawlan Communications for 18 years. Prior to that, he had worked for many companies in California in very diverse areas of analog, RF, and microwave design. Some of his work was for NASA projects. He also taught engineering part-time. Born and raised in the Los Angeles area, he attended UCLA and several other universities. He enjoyed learning many different fields and has 13 years of higher education including a Doctorate degree. Jeffrey took an uncommon interest in microwave engineering at a young age and built his first 23cm dish feed in 1961. By 1962 he was building 10GHz receivers and transmitters and he attended his first MTT Symposium exhibition in Los Angeles. He is currently on the IEEE SCV Section Board.
February 18, 2010: “RFID” by Al Scott, Besser Associates
Abstract: In 2004, Wal-Mart announced that all of their suppliers must label all products with a Radio Frequency ID tag that could read electronically from distances up to 20 feet. A decade earlier Wal-Mart had issued a similar directive about bar code labeling, that had given birth to the bar code industry.
The system reader transmits an RF interrogation signal of several watts to the merchandise. Eighty percent of the RF signal, which is at the microwatt level when it reaches the RF label, is rectified and used to power the RF chip. The chip then modulates its information onto the remaining incident RF power, and transmits it back to the reader. The modulated information signal from the chip, when in gets back to the reader, is at the picowatt level.
Examples of the various antennas from tags and readers will be shown. Received RF signal strength will be calculated.
Bio: Al Scott received his BS and MS degrees in Physics from Stanford and Cal Tech, respectively. For 35 years he specialized in the development of high power traveling wave tubes for radar, electronic warfare, and satellite communication at Hughes, Sylvania, and Varian. He also worked on the development of CT scanner tubes at AXR. For the last 12 years, he has been an instructor for Besser Associates, teaching on RF and wireless devices and testing. Mr Scott has written Cooling of Electronic Equipment and Understanding Microwaves, which were published by Wiley. He has coauthored RF Measurements for Cellular Phones with Rex Frobenius, also published by Wiley.
January 21, 2010: “Channel Surfing: Managing Propagation in Broadband Wireless Systems” by Dr. Derek Shaeffer, InvenSense, Inc.
Abstract: Broadband wireless systems such as WiMAX and LTE are poised to revolutionize mobile internet access. However, with downlink data rates in the 10-100Mb/s range and cell radii on the order of 1-5km, these emerging, carrier-class broadband wireless systems face significant challenges when it comes to managing the deleterious effects of wireless propagation. These challenges are met in both systems with OFDMA modulation which is uniquely suited to the vagaries of the wireless channel. In this talk, we will explore the propagation factors that make broadband wireless communication such a challenge and how OFDMA-based systems manage and mitigate these factors.
Bio: Derek K. Shaeffer received the BSEE degree from the University of Southern California in 1993, the MSEE degree from Stanford University in 1995 and the Ph.D. degree from Stanford University in 1999, for which he did early work in the field of RF CMOS, demonstrating the world’s first CMOS GPS receiver. His 1997 paper on CMOS low-noise amplifiers is among the most frequently cited papers in the Journal of Solid-State Circuits with over 150 citations to-date. He is the author or co-author of eleven issued patents and several pending patents, twenty papers and a book on CMOS RF design. He has worked professionally in the fields of test instrumentation, semiconductor memory, optical and wireless communications. Dr. Shaeffer has also served as Associate Editor of the Journal of Solid-State Circuits. He is currently a Director of IC Design with InvenSense, Inc., where his work is focused on MEMS gyroscopes.