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An automated 1-kHz null-balance receiver for precision RF and microwave attenuation measurements and standards

An automated 1-kHz null-balance receiver for the RF attenuation measurement system based on the dual-channel intermediate frequency substitution method was constructed and examined. A commercial programmable inductive voltage divider (IVD) was applied as its attenuation reference; however, highly accurate voltage ratios were ensured by the developed voltage ratio standard system. It is shown that the uncertainties caused by the imperfect voltage ratio of the IVD were less than 0.001 dB for attenuation measurements up to 60 dB. Comparison on attenuation measurements between the proposed automated receiver and the manual accurate one, were carried out in some microwave frequencies and good agreements were obtained.