| The Y-type hexagonal ferrite based FCL (Ferrite Coupled Lines), which is the main component of the Y-type in-plane circulator, was analyzed using the coupled mode theory. The even-mode and odd-mode field distribution was calculated with full wave analysis in a quasi-static model. A computer program was created to perform the full wave analysis, which when combined with the coupled mode theory, gave the optimum length of the device.;A novel in-plane circulator structure, MMFCL (metal magnetic film coupled line) circulator that uses metallic magnetic material instead of ferrite is presented. A long "needle" geometry of the metal magnetic strip was used to provide a strong effective uniaxial anisotropy field along the coupled lines length's direction, and at the same time it minimized the loss caused by the metallic characteristics of the metallic material. Simulations were performed with Ansoft Inc. HFSS(TM) and the optimum length of the device was obtained based on coupled mode theory. Simulation results show that the insertion loss S21 and S32 are better than -4dB, and the isolation S12, S23 and S31 are lower than -13.5 dB from 36.5GHz to 39.5GHz. |
