A programmable CMOS transceiver for structural health monitoring

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 V pp 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 μm CMOS process and has been validated using (2D) damage localization on an SHM test bed.