Meeting Notice

Southeastern Michigan


The IEEE Southeast Michigan EMC Society presents


Comparison of Methods to Evaluate the Performance

of a Three-Meter Semi-Anechoic Chamber


Presented by: Robert F. German

Tuesday, January 11, 2000 at 6:00 PM

MIRA North America

47523 Clipper Street Plymouth, MI 48170


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This is a FREE event. Snacks and refreshments will be provided at 5:45 PM.

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Comparison of Methods to Evaluate the Performance

of a Three-Meter Semi-Anechoic Chamber


Robert F. German

German Training and Consulting, LLC

Boulder, CO


Charles L. Devor Jr.

Lehman Chambers

Chambersburg, PA



Procurement of a state-of-the-art three-meter semi-anechoic chamber requires a thorough understanding of the two methods commonly used to evaluate chamber performance. The first method compares chamber performance to a theoretical model that employs free-space antenna factors, and the second method directly compares a chamber to the measured performance of a near-ideal Open Area Test Site (OATS). These methods will be used to evaluate a state-of-the-art chamber and their advantages and disadvantages will be discussed. It will also be explained how chamber performance is currently unregulated because the accepted interpretation of American National Standards Institute (ANSI) C63.5-1988 allows a chamber to be directly compared to an unspecified OATS.


Robert F. German is the manager of the German Training and Consulting, LLC. He teaches EMC training seminars, and consults on the design of digital devices and EMC test facilities. He is a NARTE certified EMC engineer, a Senior Member of the IEEE, and a member of the ANSI C63 working group on International Reference Antennas.

Prior to 1990, Mr. German was a Senior Engineer at the IBM Boulder EMC Laboratory where he was responsible for reducing the radiated emissions and improving the RF immunity of printed circuit boards used in diskette drives, printers, and copiers. Furthermore, he developed techniques for performing radiated EMI measurements and evaluating test sites in the VHF/UHF range. Mr. German pioneered the volumetric site-attenuation measurement technique for alternate test-sites specified in ANSI C63.4 and EN 55022, explored the use of a monopole antenna for EMI and site-attenuation measurements, and instituted three research projects at the University of Colorado to predict and optimize the performance of RF semi-anechoic chambers.

From 1974 to 1979, Mr. German developed communications software for facsimile machines, laser printers and ink-jet printers at IBM Boulder. He also investigated open waveguiding structures using a microwave model while pursuing the MSEE degree.

He received the MSEE degree from the University of Colorado, Boulder in 1979, the BSEE degree from the University of Miami, Coral Gables, FL in 1974, and was born in Bridgeport, CT in 1952.