RF power measurement in D-band using down-converter calibrated by three-mixer method

Abstract

To establish an RF power standard above 110GHz, we have developed a measurement system using a down-conversion mixer with a spectrum analyzer, and the conversion loss of the mixer was determined by the three-mixer method. This method measures the three transmission S-parameters (S₂₁) of three mixer pairs using a vector network analyzer. The experimental results proved that the three-mixer method can determine the conversion loss of mixers with an uncertainty of 0.5dB (level of confidence: 95%) in the entire range of the D-band. Using this uncertainty and the uncertainty of the spectrum analyzer, the proposed system can measure the RF power in the D-band with an uncertainty of less than 2.0dB.