EVALUATION OF ELECTROMAGNETIC COMPATABILITY (EMC) COMPLIANCE CHAMBERS.

NIST staff presented a paper, Evaluation of an EMC compliance chamber using an ultrawideband measurement system, at the Antenna Measurement Techniques Association meeting in Philadelphia. This technique summarized the results of a joint NIST-industry measurement effort that was carried out to develop fast and low-cost absorber-lined chamber evaluation techniques. This effort was in response to the fully anechoic room (FAR) proposal that is currently being considered by the European Community (CENELEC & IEC). The NIST team studied the FAR proposals and saw that the proposed measurement techniques were costly, cumbersome and time-consuming. In addition, the quasi free-space reference defined in the document presents a major safety hazard since it requires measurement personnel to operate at heights in excess of 8 m. The NIST measurement system eliminates the need for a quasi free-space reference, and significantly reduces measurement time and associated costs. The key to this system is the use of NIST-developed transverse electromagnetic horn antennas with a short impulse response duration that permits the use of time gating to obtain an equivalent free-space reference. The ability of the NIST system to resolve scatterers within the chamber environment system represents a quantum leap forward in chamber evaluation technology.