Design and Simulation of Multiband Coplanar Isolators Using Ferrimagnetic Substrate (YIG and BaM)

Abstract

This work focuses on the need for smaller non-reciprocal components in modern communication systems. A new coplanar waveguide (CPW) isolator design is proposed, which includes a High-Impedance Wire (HIW) structure in the ground plane. Using full-wave simulations, it is shown that the operating frequency of a fixed HIW-CPW design can be adjusted by choosing the appropriate ferrite material: Yttrium Iron Garnet (YIG) operates in the K-band, while Barium Hexaferrite (BaM) operates in the U-band. Adding an alumina layer further improves performance. A compact 9-slot design with alumina achieved very high non-reciprocity (36.4 dB ENR) with low insertion loss (0.4 dB). This study demonstrates a flexible approach to realizing compact, high-performance isolators that can be tuned to different frequency bands through material selection and structural design