Study on Dual-End Dynamic Electrical Impedance Matching Method for Dual-Frequency Ultrasound Transducers

Dual-frequency ultrasound transducers, as a core component of dual-frequency ultrasound imaging technology, usethe transmission and reception of two different frequency signals to optimiseimaging depth and resolution. Electrical impedance matching iscrucial for signal transmission and reception. However, existing studies on electrical impedance matching primarily focus on the transmission or reception of ultrasound transducersat a single frequency, failing to achieve broadband matching for dual-frequency transducers during both transmission and reception. This paper proposes a dual-end dynamic electrical impedance matching method for transmitting and receiving ultrasound transducersthat achieve dual frequencies by using different vibration modes. This method employs a dual-channel gating mechanism to achieve dual-end matching for transmission and receptionwithout mutual interference. It supports flexible network topology switchingand component parameters, and uses the Nelder-Mead simplex method for rapid calculation of component parameters. Experimental results demonstrate that the dual-end dynamic electrical impedance matching method significantly enhances the peak-to-peak voltage (V_pp) and −6 dB bandwidth of echoes and imaging signal-to-noise ratio (R_SN) across dual-frequency bands. In the 10 MHz band, the V_pp, −6 dB bandwidth, and R_SN improved by31.9%, 29.6%, and 14.8%, respectively, while in the 30 MHz band, these values increased by 37.7 %, 49.0 %, and 21.4 %. This method significantly improves the imaging performance of ultrasound transducers at different operating frequencies, providing important support for the advancement of dual-frequency ultrasound imaging technology.