September 21, 2000: “Electromagnetic Simulation and Optimization of Antennas for Wireless Applications” by Dr. Jian-X. Zheng, Zeland Software, Inc.
Abstract: In the last a few years, the wireless communication industry, the semi-conductor and computer industry have expanded tremendously. On one hand, the development of the high frequency and high speed electronic industries require more and more accurate and flexible simulation tools to improve the design efficiency and design capability. On the other hand, the speed improvement in modern computers has made the design tools based upon rigorous numerical simulation practical.
Electromagnetic simulators are accurate and powerful simulation and design tools for many different electronic design applications. Full-wave electromagnetic simulation algorithms numerically solve the Maxell’s equations governing the macro-electromagnetic phenomenon. When it is well implemented, full-wave electromagnetic simulators can be very accurate and powerful. When used properly, they are able to yield single-pass designs and reduce the design cycles and costs significantly.
The rapid development of the wireless industry has created a challenging task and big opportunity for antenna designers. Every wireless device requires at least one antenna. There are many different requirements for different antennas for difference devices. For example, the antennas should be small size and light weight. They normally do not have a big ground plane. One single antenna may be required to operate at 2 to 3 bandwidths. They may be required to be omni-directional or circular polarized. In order to achieve the design goals, electromagnetic simulators are necessarily needed.
In this talk, Dr. Zheng will briefly explain the fundamental of electromagnetic simulation. He will also show how electromagnetic simulation can be applied to general antenna simulation and design. Different antenna examples will be shown in the presentation.
Bio: Dr. Zheng received his Ph.D. degree in Electrical Engineering from University of Colorado at Boulder in 1990. He joined EEsof, Inc. in 1991. Dr. Zheng started the Zeland Software, Inc. in 1992, specializing in electromagnetic simulation and optimization. Dr. Zheng is the major developer of the company’s major products: the IE3D Electromagnetic Simulation and Optimization Package and the FIDELITY Full-3D Time Domain Electromagnetic Simulator.
June 20, 2000: Annual Banquet “RADAR before the Magnetron” by Rick Ferranti, SRI International
Abstract: The late 1930’s was a period of intense development in high-frequency radio technology, focused by the desperate need for air defense in the impending world conflict. The result of these research efforts was radar – deployed internationally in 1939 – but its full potential was not realized until the invention of the microwave cavity magnetron in 1940. Until then, early WWII radars operated at meter wavelengths, using techniques borrowed from the shortwave and early television disciplines.
Using vintage film clips, modern computer analysis, and period hardware, this 45-minute presentation will highlight the technical innovations, operation, and legacies of two of the more famous early radars deployed by the Allies, the British Chain Home and the American SCR-270.
Bio: Rick Ferranti is a San Francisco native and grew up in the SF Bay Area, where he attended Santa Clara University. Rick moved to the East Coast in 1976 to pursue a graduate education, and somehow got stuck there until last year. Since returning to the Bay Area, Rick has been employed by SRI International as a research engineer for radio frequency and microwave communications and radar systems. Formerly, he was an Associate Leader of the Air Traffic Control Systems Group at MIT Lincoln Laboratory in Lexington, Massachusetts. He managed Laboratory activities for the FAA’s new terminal and older en route primary radar systems, and participated in special studies on radar hardware, antennas, signal processing, and surveillance for both the FAA and the Defense Department. Rick obtained SMEE and SBEE degrees in Electrical Engineering from MIT in 1984. In addition, he holds a graduate humanities degree from Harvard University (1978), a BA from Santa Clara University (1976), and was appointed University Fellow at Boston College (1978 – 80). Rick enjoys studying the history of technology, particularly the development of mining, telegraph, radio, and radar techniques from the 19th century to the present. He lives in San Carlos with his wife and two sons, and a garage full of old electronics.
May 26, 2000: “CONTOUR BEAM REFLECTOR ANTENNA AND ARRAY DESIGN/ANALYSIS” A SHORT COURSE Conveniently located on-site of the Phased Array Conference sponsored by TICRA and IEEE AP-S Los Angeles & San Francisco Chapters
- Design and analysis of shaped reflectors, multi-feed, and array antennas
- Design Techniques for synthesis/analysis of contoured beams
- Geographical definition of coverage area requirements via COBRAW
- Inclusion of antenna pointing error affects
- Object oriented software suite presented (POS4 and GRASP8)
- Corrugated excitation feed horn designs considered
- Course presented by TICRA – a industry leading consultant in the aerospace community
April 20, 2000: “Patch Antenna Reflect Arrays” by Dr. Anthony Jennetti, TRW ESL
Abstract: Reflect Arrays are being increasingly used in antenna applications. This presentation outlines the design principles for passive reflect arrays and points out potential pitfalls in some design approaches. The talk shows a means of broadening the bandwidth of patch reflect arrays by employing parasitic elements in the design of the dual polarized patch antenna element. The design of the reflect array is broken down into four separate parts-the individual patch, the array, the delay lines, and the optical design of the reflect array system. The various topics of importance are array element density, minimization of surface-wave effects, array element pattern coverage, array topology, feed-horn type and illumination and spillover. Experimental results are presented in detail for a reflect array that illustrate some of the design principles.
Bio: Anthony Jennetti earned his Ph.D. and M.S.E.E degrees in Electrical Engineering from Ohio State University and his B.S.E.E. from Penn State University. At Ohio State he was employed as a Research Associate at the ElestroScience lab where he obtained three antenna patents.
He has been with ESL (a division of TRW) since 1970 and is currently a principal engineer. Other experience includes Randtron (L-3 Communications) from 1984-1986 where he was manager of Microwave Engineering. He has served as past chairman of the Local Antenna and Propagation Society Chapter and has chaired or served on several International AP-S/URSI Symposium Arrangements committees. He is currently co-chairman of the Arrangements committee for the 2004 Monterey APS/URSI International Symposium.
March 21, 2000: “Nonlinear Diffusion and Internal Voltages in Conducting Ferromagnetic Enclosures Subjected to Lightning Currents” by Dr. William A. Johnson, Sandia National Laboratories
Abstract: The voltage inside a conducting ferromagnetic enclosure, excited by direct attachment of lighting is determined. A nonlinear approximate model is constructed and solved analytically to model the magnetic field diffusion through the enclosure wall excited by a filament current. This model gives the internal voltage waveform (at very early times it forms a rough approximation to the solution). The solution (including the early time behavior) for an attached current carrying conductor of a large radius is also given. The model is constructed by use of known nonlinear saturation front theory. This talk also considers non-negligible magnetic flux behind the saturation front (in the saturation region), and shows that this saturated flux results in a simple additive time shift to the penetration of the front.
Bio: William A. Johnson was born in Beverly, MA, on April 16, 1951. He received the B.S., M.A., and Ph.D. degrees in mathematics with a minor in physics from the University of Arizona, Tucson, AZ, in 1972, 1974, and 1978, respectively.
He has been with Sandia National Laboratories, Albuquerque, NM, since 1983 and is currently a senior member of the technical staff. Other experience includes Lawrence Livermore National Laboratories (1981-1983), Science Applications, Inc. (1979-1981), and University of Mississippi (1978-1981), where he served as an assistant professor. He also served as and adjunct associate professor for the Department of Mathematics at the University of New Mexico (1992-1994).
Dr. Johnson is a member of Commission B of the International Union of Radio Science.
February 9,, 2000: “Satellites for Personal Communications and Proposed US Multimedia Satellites” by Dr. John Evans, IEEE AP Distinguished Lecturer, VP & CTO, COMSAT Corporation
Abstract: The talk briefly reviews the growth of satellite communications for fixed services (voice and data) and mobile services (to ships and aircraft). Currently, about 25% of the voice traffic between countries, and essentially all of the TV traffic is carried by satellite. In addition, there is considerable growth in data as ISPs in overseas markets seek better access to the U.S. backbone. Domestically, satellites are used principally for distributing TV, both to cable head ends and directly to the home, though in some parts of the world (e.g. the Philippines) they are still used for voice traffic.
Mobile satellite communications is being provided to ships, aircraft and land vehicles. Recently, a new service was inaugurated to serve individual users via hand-held, cell-like phones by a company called Iridium, and other projects for the same type of service are in process. Two new systems (Globalstar and ICO) aim to provide a global service, while others (ACeS, Thuraya etc.) are regional.
A new use for satellites will be to link consumers and small offices directly to the Internet. Worldwide, several hundred applications have been filed with the ITU for delivering such service. Here in the U.S. the FCC has conducted four Notice of Proposed Rule Makings, offering companies the opportunity to file for new satellite systems operating a) in the Ka-Band, b) in the Q/V-Bands, and c) as non-geostationary satellites in the Ku-Band. The balance of the talk is spent describing some 13 U.S. Ka-Band systems, that the FCC has so far licensed.
The 13 U.S. licensed systems will all operate at Ka-Band, where rain fading introduces considerable design problems. These are described and the ways that they are to be overcome are outlined. All of the systems entail extremely large investments ($ billions), so that it is likely that only a few will actually get built. The talk concludes with the author’s best guesses as to which these are likely to be.
Bio: Dr. John V. Evans is the Vice President and Chief Technical Officer of COMSAT Corporation, a position he assumed in September 1996. Prior to this Dr. Evans was the President of COMSAT Laboratories which he joined in April 1983. COMSAT Laboratories has a staff of 300, and annual budget of about $40 million, and is the largest research center devoted entirely to satellite communications research.
Before coming to COMSAT, Dr. Evans was with the M.I.T. Lincoln Laboratory which he joined in 1960. He is a graduate of Manchester University, England with a degree in Physics.
He is a Fellow of the Institute of Electrical and Electronics Engineers, and a Fellow of the American Institute for Aeronautics and Astronautics as well as a member of the National Academy of Engineering.