Advances in state-of-the-art of surface acoustic wave (SAW) device technology will require better substrate materials than those currently available. Calculations of the surface acoustic wave properties of several materials including the quartz derivatives berlinite (A1PO4 ) and 0-eucryptite (0-Li Al SiO4), certain sulfosalts, and a composite structure, have produced several temperature-compensated crystallographic orientations with greater piezoelectric coupling than that of ST cut quartz. These materials make possible the development of improved broadband, low insertion loss devices with temperature-independent performance characteristics. Methods of growing improved aluminum nitride (A1N) are being studied. Because the SAW velocity of this material is about twice that of currently used materials, A1N promises to extend the upper frequency limit of SAW devices beyond 2 GHz.