A Simplified Procedure for Impedance Measurement using Multi-State Radiometer

A new noise procedure for measurement of the complex reflection coefficient using a multi-state RF total power radiometer is introduced. It utilises a novel isothermal model describing noise power measurements. The model enables calibration of the system with at least six ordinary impedance standards and subsequent determination of an unknown impedance from at least three noise power measurements made in different states of the radiometer. Experiments show that despite much lower power of the noise excitation the measurement accuracy can be comparable with that of vector network analyser.