Applications of surface acoustic wave (SA W) and shallow bulk acoustic wave (SBA W) devices are reviewed. SA W-device coverage includes delay lines and filters operating at selected frequencies in the range from about 10 MHz to 11 GHz, modeling with singlecrystal piezoelectrics and layered structures, resonators and lowloss filters, comb filters and multiplexers, antenna duplexers, harmonic devices, chirp filters for pulse compression, coding with fixed and programmable transversal filters, Barker and quadraphase coding, adaptive filters, acoustic and acoustoelectric convolvers and correia tors for radar, spread spectrum, and packet radio, acoustooptic processors for Bragg modulation and spectrum analysis, real-time Fourier-transform, and cepstrum processors for radar and sonar, compressive receivers, Nyquist filters for microwave digital radio, clock-recovery filters for optical fiber communications, fixed-, tunable-, and multimode-oscillators, and frequency synthesizers, acoustic charge transport (ACT), and other SA W devices for signal processing on gallium arsenide, SA W sensors, and scanning acoustic microscopy. SBA W-devices applications include gigahertz delay lines, surface transverse wave resonators employing energy-trapping gratings, as well as oscillators with enhanced performance and capability.