A simplified six-port model in the radio frequency regime

Abstract

A simplified six-port reflectometer design for the high power radio frequency regime is demonstrated. First a new calibration method for the often-used six-port reflectometer design is presented, where one of the signals is proportional to the forward power only. The presented method is much simpler than other methods given in the literature and, in contrast to these methods, it does not use an overdetermined set of calibration constants. Then a second design restriction is applied, namely that one of the other signals is proportional to the reflected power only. It is shown that this will lead to a nonlinear set of equations with only four calibration constants to be determined. By combining these two results the nonlinear method can be linearized. In doing so the number of calibration constants is increased to six, thereby creating an overdetermined system. It will be shown that, based on noise sensitivity and computational effort, this linearized, overdetermined method is preferred over the nonlinear one.