Analysis of the Microstrip Circulator with a Magnetized Ferrite Sphere in Millimeter Wave through FDTD Method with LS-SVM and PSO

摘要

Circulator is a device for isolating different parts of an electromagnetic circuit from one another. Three-port circulators have been extensively used in duplex communications systems for separating the wave received and the wave to be transmitted. Microstrip circulator is much more compatible with monolithic integrated circuit than stripline circulator and waveguide circulators [1]. In [1], a novel microstrip circulator with a magnetized ferrite sphere is proposed for various millimeter wave communications. A ferrite sphere covering with a metal cap is placed at junction center hole of three microstrip arms and fixed firmly by a low loss adhesive. In this way, it is easy to change circulating frequency of the circulator simply through replacing ferrite sphere with different diameters.