Satoru Shinmura

Mechanically tunable MSW bandpass filter with combined magnetic units

An MSW (magnetostatic wave) bandpass filter with combined magnetic units composed of main and submagnetic units has been developed. Its volume is reduced to one fifth that of conventional yttrium-iron-garnet (YIG)-sphere filters. The filter can be tuned mechanically and keep the same shape of transmission response at 2.5 approximately 2.75 GHz. The insertion loss can be kept less than 3 dB within 20-MHz bandwidth by adjusting the magnetic field distribution.<<ETX>>

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.<<ETX>>

A miniaturized low-spurious 1.9 GHz MSW band-pass filter using YIG resonators with multi metal rings

A simple technique for forming multiple metal rings on both sides of a YIG element has been developed to suppress the spurious responses of YIG resonators. By using this resonator, a 10-mm*5-mm*4-mm/sup 3/ two-stage MSW (magnetostatic wave) bandpass filter has been developed. The insertion loss is about 2 dB at 1.9 GHz and the suppression of spurious response is 25 dB. The filter is useful for signal processing in the circuits of portable microwave telecommunication sets because of its compact dimensions and excellent filter characteristics.<<ETX>>