Dynamic Beamforming Strategy for Sidelobe Level Suppression in Piezoelectric Micromachined Ultrasonic Transducer (PMUT) Sparse Arrays

In this paper, we proposed a novel method to suppress the sidelobe level for a presented quasi-periodic sparse 2D array based on piezoelectric micromachined ultrasonic transducer (PMUT) technology. We applied a dynamic apodization based on Dolph-Chebyshev weights to the transducer for both transmitting and receiving for different steering angles. The apodization weights were obtained by iterative calculations in a simulation model built with Field II. Based on the calculated weights, intensity profiles were simulated and compared with that without weighting. The results showed that the side lobe level was reduced from - 14.3 dB to -38 dB when no steering angle, and from -12 dB to - 16 dB when the steering angle was 45°. It is shown that the side lobe level was largely suppressed, with the cost of an acceptable larger main lobe.