  We describe a highly-integrated CMOS transceiver for active structural health
monitoring (SHM). The chip actuates piezoelectric transducers and also senses
ultrasound waves received by the same or another transducer. The transmitter
uses an integer-N frequency synthesizer and pulse-width modulation (PWM) to
generate low-distortion, band-limited waveforms up to 12.7 Vpp with center
frequency from 0.1-2.75 MHz. The integrated offset-canceling fully-differential
receiver has programmable gain and bandwidth, and uses quadrature demodulation
to extract both amplitude and phase of the received waveforms for further
signal processing. The transceiver was fabricated in a 0.5 um CMOS process and
has been validated using (2D) damage localization on an SHM test bed.
