A review of the properties of acoustic surface wave materials

The various material design parameters which must be considered in order to obtain optimum surface wave device performance in the UHF and microwave frequency regions are reviewed. Combined beam steering, diffraction loss curves are provided as a function of the basic material parameter, the slope of the power flow angle. Methods for designing optimum uniform periodic interdigital transducers including finger ohmic loss, lossy tuning elements, and parasitic capacitance have been extended to account for beam steering and diffraction. A minimal diffraction orientation on Bi12GeO20 having diffraction retarded by at least two orders of magnitude over isotropic materials is discussed. The presently available tradeoffs between temperature sensitivity and coupling coefficients are also presented.