Reverberating Asymmetric TEM Cell For Radiated EMC/V And SE Testing, 10 KHz-18 GHz

This paper describes work in progress at the National Institute of Standards and Technology (NIST) to develop a single, integrated facility for electromagnetic compatibility/vulnerability (EMC/V) and shielding effectiveness (SE) testing over the frequency range of 10 kHz to 18 GHz. The facility consists of an asymmetric (offset center plate) TEM cell, 1.01 m x 1.20 m x 2.98 m in size, with two cavity mode tuners, configured as a TEM transmission line-driven, modestirred chamber. TEM test fields are generated in the chamber at frequencies below multimode cutoff (= 150 MHz), and mode-stirred test fields are generated at frequencies above multimode cutoff. The test volume in the cell is 0.5 m x 0.6 m x 0.6 m. The paper discusses the cell design, advantages and limitations for its use, the theoretical basis for its operation, and the experimental approach for its use in SE or EMC/V testing. Results are given of the evaluation of the cell's operational parameters including VSWR, E-field amplitude versus input power, tuners' effectiveness, and test volume E-field uniformity .