A Broadband Resonant Noise Matching Technique for Piezoelectric Ultrasound Transducers

A novel resonant noise matching technique is proposed to improve the sensitivity and output SNR of ultrasound receivers. Diverse from the power matching, the resonant noise matching technique proposed in this paper applies resonant LC networks to raise the transducers' input impedance to a high impedance. As a consequence, in addition to the function of improving the output signal strength, the prominent advantage of the resonant noise matching technique is that the passive gain provided by the matching network can reduce equivalently the receiver's input-referred noise and thus obtain the minimum noise figure. Furthermore, broadband matching which can cover the transducers' working bandwidth is also developed to reduce the ringing in received signals, which can significantly improve axial resolution in applications of imaging. For this, an accurate electrical model extended from Butterworth Van-Dyke (BVD) model is obtained to co-simulate with the new matching network in the design. Measurement results show that, the output signal is improved by 5 times through the proposed technique, which is 66.7% larger than that of conventional methods. In addition, the sensitivity of the receiver is significantly improved by more than 10.4 dB which is beneficial for piezoelectric ultrasound transducers in a variety of applications.