FPGA-Based Ultrasonic Transducer Signal IIR Filtering Treatment

During the operation of the ultrasonic transducer, factors such as temperature, load, and wear cause the resonant frequency of the transducer to deviate. Therefore, it is necessary to quickly and real-time track the resonant frequency of the ultrasonic transducer. The voltage and current signals under the working state of the transducer are severely interfered by harmonics, which greatly affects the realization of frequency tracking. Based on the principle of IIR filtering, the signal is filtered with FPGA as the core, and a digital parameter configurable IIR filter is designed for different resonant frequency transducers. The received original signal is filtered for frequency tracking. This article uses a 40kHz resonant frequency transducer as the experimental object. It has been verified that this digital filter can effectively filter out harmonic signals and has practical guiding significance for achieving frequency tracking of ultrasonic transducers.