A low-loss magnetostatic wave filter using parallel strip transducer

A configuration for a magnetostatic forward bulk wave (MSFBW) filter is proposed. The proposed filter uses seven parallel strip transducers and three metal disks loaded on YIG (yttrium iron garnet) film. The radiation impedance of the filter was calculated using a Fourier transform relation between the MSFBW field amplitude and the transducer spatial current distribution. The dependence of YIG film thickness on the 3-dB bandwidth is shown. The transducer design, considering radiation impedance matching using parallel strips, yields a large coupling coefficient with the YIG film. An insertion loss of 6 dB was achieved in the 0.7-5.2-GHz band, and an insertion loss of 4 dB was achieved in the 2.8-3.9-GHz band.<
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