Low uncertainty broadband EMC measurement using calculableprecision biconical antennas

摘要

It has been extensively studied and reported that uncertainties aslow as 0.11 dB for antenna factor (AF) characterization can be achievedusing FitzGerrell (1986) dipole antennas. Although it has been suggestedto use these dipoles for swept frequency measurements, broadbandbiconical antennas have not been investigated and reported in literaturein a similar manner. A pair of precision biconical antennas wasconstructed to investigate this possibility. The antennas werenumerically simulated in the frequency range of 30-300 MHz above aninfinite conducting ground plane and in free space. The numericalresults were combined with the measured S-parameters of the baluns togive the theoretical site attenuation. It has been shown that thestandard site method adopted by ANSI C63.4 can have systematic errors innormalized site attenuation larger than 4 dB using free-space biconicalAFs from 30 to 300 MHz. The numerical approach described in this paperis shown to be capable of providing theoretical site attenuation valuesthat are within a fraction of a dB of measured results