The Calibration and Performance of a Microstrip Six-Port Rdlectometer

The calibration and performance of a microstrip six-port reflectometer consisting of only one six-port coupler is discussed. The positions of the centers of the impedance-locating circles are determined from the calibration constants and their frequency behavior is illustrated. The results of measuring some terminations by the reflectometer and two HP network analyzers are compared within the frequency range from 0.5 GHz to 8 GHz. From this comparison tke useful bandwidth of the reflectometer is found to be from 0.5 GHz to 5.5 GHz.