A simplified six-port model in the radio frequency regime

A simplified six-port reflectometer design for the high power radio frequen cy regime is demonstrated. First a new calibration method for the often-use d six-port reflectometer design is presented, where one of the signals is p roportional to the forward power only. The presented method is much simpler than other methods given in the literature and, in contrast to these metho ds, 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 lea d to a nonlinear set of equations with only four calibration constants to b e determined. By combining these two results the nonlinear method can be li nearized. In doing so the number of calibration constants is increased to s ix, thereby creating an overdetermined system. It will be shown that, based on noise sensitivity and computational effort, this linearized, overdeterm ined method is preferred over the nonlinear one. (C) 2000 American Institut e of Physics. [S0034-6748(00)04009-0].