Analysis of diodes used as precision power detectors above the square law region

The deviation from square law found in diode power detectors at moderate power levels has been modeled for a general system consisting of a number of diode detectors connected to a common arbitrary linear passive network, containing an approximately sinusoidal source. This situation covers the case of the six-port. The diodes are isolated from each other at DC. No assumption has been made about diode impedances, so that the diodes are interacting with the network as well as with each other at the fundamental frequency and at the harmonics. By applying the model the deviation can be eliminated if an extra-set of measurements is made in situ. For precision measurements the maximum power level can be increased by about 10 dB. The dynamic range can thus be increased sufficiently to enable fast measurements to be made with an accuracy of 10/sup -3/ dB.<>