Synergistic Enhancement of Acoustic Response in Phased Array Ultrasonic Transducers Utilizing Alternating Current Poling and Acoustic Reflection Layers

The relationship between the bandwidth and sensitivity of ultrasonic transducers (UT) is characterized by a mutually restrictive nature. Consequently, the collaborative enhancement of the acoustic response of the UT is essential for achieving high-quality ultrasound imaging. This study explores the synergistic improvement of the acoustic response in phased array UTs through the implementation of alternating current (AC) poling and the incorporation of an acoustic reflection (AR) layer. Simulation results indicate that the -6 dB bandwidth of the phased array, when utilizing co-optimized structures, exhibits varying degrees of enhancement compared to alternative designs. Furthermore, the increase in echo amplitude associated with the co-optimized structure is significantly greater than the cumulative echo amplitude derived from individual optimization structures, suggesting a substantial acoustic coupling enhancement effect between the two design frameworks. Empirical test results confirm that phased arrays featuring the co-optimized structure achieve a larger -6 dB bandwidth, with improvements reaching up to 89.3% compared to direct current (DC) poling phased arrays. Additionally, the relative sensitivity of the co-optimized phased arrays is 8.39 dB greater than that of the DC poling phased arrays, surpassing the sensitivity observed in the superposition of the single optimized structures, thereby validating the theoretical predictions established in prior simulations. Thus, the coupling optimization effect of the two design structures effectively mitigates performance degradation associated with individual design approaches, enhances the acoustic properties, and ultimately contributes to the advancement of ultrasonic imaging quality.