30MHz Attenuation Standard Using Binary Phase Modulation Method

30MHz attenuation measurement system which uses a ratio transformer as the standard attenuator instead of a piston attenuator is designed and examined. Higher accuracy at low attenuations and easier maintenance are expected in the system than in the conventional one. Homodyne detection for the binary phase modulation method and heterodyne detection for the intermediate frequency substitution method are examined for 30MHz-1KHz attenuation conversion.