New measurement method of RF absorber characteristics by large square coaxial line

A large square coaxial line has been developed for precise evaluation of RF absorbers, especially at frequencies below 100 MHz. The coax requires no metal reflector at the bottom of RF absorber test sample, so that a transmitted wave as well as a reflected wave can be measured. The characteristics of cascaded absorbers are calculated from measured data on each absorbing material. With the coax, a precise evaluation of the performance degradation due to the air gap influence of the ferrite absorber can be made.<
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