Ferrite-Coupled Line Circulator Simulations For Application at X-Band Frequency

We have designed and simulated a circulator circuit in which the magnetization aligns along the plane of an yttrium iron garnet (YIG) film. For an X-band frequency (8-12 GHz) circulator we have utilized a YIG slab (~200 mum thick) with saturation magnetization (4piM_S ) and ferrimagnetic resonance (FMR) linewidth (DeltaH) of ~139.26 kA/m and 10 Oe, respectively. Broadband circulator operation was realized for frequencies above FMR, f=5 GHz. The applied FMR field was 79.58 kA/m. The Ansoft HFSS software suite was used to simulate the circulator response. The insertion loss S₂₁ and the isolation S₁₂ were calculated to be ~0.9 dB and ~-52 dB, respectively, with ~15% bandwidth at the center frequency of 10.1 GHz. We believe that this in-plane circulator design may enable high performance with significant volume and weight reduction