The effect of the dielectric gap between a transducer and a ferrite film on the excitation of magnetostatic waves

Experimental results are presented on the effect of the dielectric gap between transducer and YIG film on the excitation of surface and bulk magnetostatic waves (SMSWs and BMSWs) in devices for the analog processing of electromagnetic signals. It is shown that a widening of this gap leads to the disappearance of the peaks of SMSWs with high wavenumbers. For the SMSW peak there exists only one gap value for which the wave amplitude is maximal, while for the BMSW peak there exist several values where the wave amplitude is maximal. The nonreciprocity of SMSW peaks depends on the gap and is maximal for the gap that assures the highest amplitude of the SMSW peak. The introduction of a dielectric gap can be used for the matching of SMSW and BMSW devices with microwave sections.