On the modified resonance theory of waveguide circulator with various ferrite specimens

A modified resonance theory of waveguide circulator with ferrite specimen i s presented. The kernel of this theory is a two-step analysis method of all H-plane Y-junction waveguide circulator. For the first step, the ferrite s pecimens of Y-junction waveguide circulators are treated as if it were diel ectric resonators with no magnetic bias. This simplistic approach is used t o design the ferrite specimens of the circulators. Simple formulas are deve loped for determining the center frequency of the circulators. For the seco nd step, wave circulation is made possible when a pair of degenerate resona nce modes experiences different changes when the ferrite specimens are bein g magnetized. A modified analysis of joint resonance theory and simple fiel d theory is advanced to evaluate the performances of the circulators. Good agreements between the analytically obtained performance and experimental r esult of various MMW waveguide circulators are observed.