Transmission and reflection coefficients for surface transverse waves propagating under shorted metal strip gratings

摘要

Coupled-mode theory is used for the analysis of surface transverse waves (STWs) propagating under metal-strip gratings in the YZ plane of quartz. Analytical expressions are obtained for the reflection and transmission coefficients of waves propagating on rotated Y-cut substrates of weakly piezoelectric trigonal, tetragonal, or hexagonal crystals. A quadratic dependence of the stopband width on the height-to-period ratio of the electrodes is found. This is an agreement with stopband width measurements. The results can be used in the analysis of STW grating structures, particularly the two-port resonator filter.