Longitudinal-mode leaky SAW resonator filters on 64/spl deg/ Y-X lithium niobate

Y-parameter modeling is applied to obtain the frequency response of a first/third dual-mode longitudinally-coupled leaky-SAW (LSAW) resonator-filter on 64/spl deg/C Y-X LiNbO/sub 3/. Conventional driving-point and transfer admittance relationships for SAW filters are modified to incorporate the effects of LSAW reflection and bulk-wave scattering in the interdigital transducers and are expanded to include reflection gratings with shorted-metal strips. As inferred from experiment, the grating parameters incorporate a phase-shift term to relate the anomalous dispersion of shorted gratings, as well as a modified phase-slope parameter between input and output interdigital transducers (IDT's). Good agreement is obtained with experimental results published for 836.5 MHz two- and four-pole structures in the maximum-bandwidth configuration.<
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