On the operating modes of a millimeter‐wave H‐plane partial height ferrite post waveguide circulator

A new method for analyzing a millimeter‐wave H‐plane waveguide Y‐junction circulator with a partial height ferrite post is presented. Simple formulas are developed for determining the center frequency of the circulator and the length of the ferrite rod. The lowest mode of operation is not unique and is dependent on the length of the ferrite post. Based on the newly derived formulas, several broadband 3‐mm circulators have been designed, assembled, and tested. Good agreement between the analytically obtained performance and experimental results is observed. © 1995 John Wiley & Sons, Inc.