The Phase Shift Through Symmetrical 3-Port Circulators (Short Papers)

Simple approximate formulas are derived for the phase shift through matched circulators---with and without transformer coupling---using expressions for the eigenadmittances Y₀, Y_-1, and Y₁ which have recently been proposed. These formulas allow one to predict the phase shift from measurements of the VSWR in one case and from a knowledge of the transformer admittance Y in the second. They have been confirmed experimentally for strip-Iine circulators and indicate that in this respect circulators behave like electrically long transmission devices.