Capacitive Micromachined Ultrasonic Transducer Based Airborne Pitch-Catch Measurement Modeling

Capacitive Micromachined Ultrasonic Transducers (CMUTs) are attractive for airborne ultrasonic sensing due to their wide bandwidth and high sensitivity. Building on previous modeling work, this study focuses on experimental pressure measurement and validation of CMUT performances in pitch-catch configurations. An acousto-optic approach is employed to directly measure the radiated acoustic in air, providing experimental confirmation of field uniformity along the elevation and diffraction effects along the azimuth. These results validate the lumped-element modeling framework and enable accurate correlation between simulation and measurement. In addition, a detailed receiver-side noise analysis using a transimpedance amplifier model is conducted, allowing extraction of intrinsic CMUTnoise floor and derivation of the Noise Equivalent Pressure (NEP). Together, these findings establish a validated methodology that links modeling, experimental pressure measurement, and noise characteristics, strengthening the basis for the use of CMUTs in airborne sensing applications.