Measurement of microwave absolute power with the aid of a six-port junction with four diodes

A method of calibration is proposed for six-port junctions using four integrated diode detectors. This solution enables six-port reflectometers to measure absolute powers as well as reflection coefficients. The method necessitates a single power meter for the duration of the calibration only, and a simple variable attenuator. It is applicable to MIC, MMIC or MHMIC technologies for a configuration, integrated or otherwise, in either CW or pulse mode. Using a transparent six-port junction one can measure the absolute power absorbed by any load with a probe having an unmatched impedance of 50 ohms, which is very useful in some circumstances for the nonlinear characterisation of active devices.