IEEE Electromagnetic Compatibility Chapter (EMC) Meeting

James McLean, jmclean@tdkrf.com
TDK RF Solutions, 1101 Cypress Creek Road, Cedar Park Texas

"High Intensity Radiated Susceptibility Testing Using Antenna and Quasi-static Field Generators"

Thursday March 18, 2004

5:30 - 7:30 PM

ADTRAN Campus, 5th Floor Bridge Training Room, 901 Explorer Blvd.

Contact Allan Flack at 722-4930 or aflack@ab-com.cc RSVP for Catering: Tues March 16th. Refreshments by: ERC

Abstract: Radiated susceptibility testing is typically performed over the frequency range of 10 kHz to 3GHz at distances of 1-10 meters. In particular, the testing requirements of MIL-STD 461, RS-103 recommend a minimum distance of 1 meter between the DUT and the field generating device. The high requisite electric field intensity (200 V/m) combined with equipment limitations often results in the DUT having to be placed quite close (both physically and electrically) to the field generator in order to meet the field intensity requirements. Moreover, many such tests are performed in either unlined, shielded rooms or anechoic chambers whose absorber is not capable providing anechoic behavior at the frequency at which the tests are performed. That is, the lower portion of frequency range of such tests (30 MHz and below) often lies well below the frequency range at which typical broadband absorbing materials are effective. Thus, the question naturally arises as to how well such a test actually represents a real-life situation in which a distance source, such as a radar system, illuminates the DUT.

In this presentation we will address the fundamental operation of three different types of field generating devices: (1) Antennas including typical biconical/broadband dipole antennas and hybrid broadband dipole/LPDA combinations, (2) Quasi-static electric field generators, and (3) So-called E/H quasi-static field generators. We will consider in detail the nature of the electromagnetic fields generated by these devices with particular attention being paid to the reactive and radiative near field regions. We will also discuss in some detail the interaction of such field generating devices with shielded rooms and anechoic chambers focusing on the use of such devices in the problematic frequency range in which most broadband absorber is ineffective, but typical chambers are large enough to support resonant modes (typically 1-100 MHz). Finally, we will consider the relationship between these tests and real-world EMS threats. We will discuss coupling mechanisms and how improper interpretation of data from tests can lead to inaccurate prediction of performance.

Biographical Sketch: James McLean is a senior scientist with TDK R&D corporation in Cedar Park, Texas. He is currently performing research in the areas of electromagnetic compatibility, electrically-small antennas, ultra-wideband antennas, and antenna metrology. He publishes regularly in the areas of EMC and antenna design and holds numerous patents in these areas.

Prior to coming to TDK, he was with the Department of Electrical and Computer Engineering at the University of Wisconsin--Madison where he taught electromagnetic field theory and electronics and performed research for DARPA's GLOMO project involving antennas for mobile radio equipment.

James McLean has worked at TRW Antenna Systems Laboratory in Redondo Beach where he was involved in microwave filter and multiplexer design.

James McLean received the BSEE, MSEE, and Ph.D. degrees in Electrical Engineering for the University of Texas at Austin in 1984, 1986, and 1990, respectively. His Ph.D. dissertation concerned the numerical modeling of electromagnetic radiating structures on open, layered substrates. After graduation, he spent one year in a post-doctoral position at the Max Planck Institute in Stuttgart where he performed research involving high-speed field-effect transistors.