RF attenuation measurement system with 1-kHz voltage ratio standard

A homodyne system for measuring attenuation at 10 GHz and 30 MHz is constructed and evaluated. The radio frequency (RF) attenuation is converted to 1-kHz attenuation, and the 1-kHz attenuation is measured by an inductive voltage divider built in a 1-kHz receiver. A 1-kHz voltage ratio standard (VRS) is proposed to check the accuracy of the 1-kHz receiver for maintaining long-term accuracy. The differences between the VRS and the 1 kHz receiver are smaller than 0.0003 dB for 0-40 dB. A precision piston attenuator of 30 MHz agrees with the system within 0.0018 dB for 0-30 dB. The change in measured values at an interval of one year are less than 0.001 dB. The results demonstrate that this system can be expected to reliably maintain high accuracy.<>