A microwave circuit model for a magnetostatic wave filter

A microwave circuit model for magnetostatic-wave (MSW) filters has been developed. In the circuit considered, a number of thin strips of epitaxially grown YIG films are coupled to a common input manifold. Each strip is subjected to a different bias field, thereby producing a different passband frequency. Each YIG strip has its own separate output transducer. The complex radiation impedance of the transducers takes into account the reflection from the open end of the YIG strip. The YIG channel is modeled as a transmission line with frequency-dependent impedance equal to the MSW radiation resistance. Triple transit ripple is accurately predicted. The effects of using external matching circuits and thin metal films applied to the YIG for triple transit ripple suppression are discussed.<>