A study on transducer type isolator using YIG single crystal

A transducer type isolator is proposed using tangentially magnetized YIG single crystal. The single crystal is analyzed by the finite element method. Frequency response of scattering parameters and field distribution were calculated and optimized by using high frequency structure simulator. Experiments were undertaken using a single crystal of YIG slab, and measured results corresponded well to the numerical results. Isolation ratio of 48 dB with 6 dB insertion loss and 880 MHz bandwidth around 4.2 GHz was measured. Characteristics using composite right/left-handed transmission lines (CRLH-TL) transducers were also investigated and isolation ratio of 48 dB with 5.5 dB insertion loss and 2.0 GHz bandwidth (from 3.85 GHz to 5.85 GHz) was measured. Proposed isolator has potential for high dynamic isolation ratio and wideband operation. It may be developed more with careful design of capacitive and inductive loadings of the CRLH structure.