An efficient method to analyze the H-plane waveguide junction circulator with a ferrite sphere

This paper presents an approximate, but efficient field treatment of the ne w easy-to-fabricate ferrite-sphere-based H-plane waveguide circulator for p otentially low-cost millimeter-wave communication systems, A new three-dime nsional modeling strategy using a self-inconsistent mixed-coordinates-based mode-matching technique is developed, i.e., the solutions of the Helmholtz wave equations in the ferrite sphere and in the surrounding areas are dedu ced in the form of infinite summation of spherical, cylindrical, and genera l Cartesian modes, respectively. The point-matching method is then used on the interface between the ferrite sphere and air within the cylindrical jun ction, as well as the interface between the junction and waveguides to nume rically obtain the coefficients of different orders of basis functions of t he field. Therefore, the field distributions, as well as the characteristic s of the circulator, are numerically calculated and good agreement is obser ved between the numerical results and measured data.