An Intrabody Ultrasonic Frequency Modulation Communication Microsystem Based on Piezoelectric Micromachined Ultrasonic Transducers

This paper presents an intrabody ultrasonic frequency modulation communication microsystem based on piezoelectric micromachined ultrasonic transducers (PMUTs). Frequency modulation communication was realized by regulating the DC bias applied to the PMUT array in liquid. By optimizing the PMUT design and the driving signals, this system demonstrates a resonant frequency shift from 163 kHz to 337 kHz with −8 V to +8 V DC biases in liquid. Compared with conventional communication methodologies, the frequency modulation strategy proposed operates exclusively through DC bias-controlled frequency tuning, thereby eliminating the need for high-frequency carriers and sophisticated circuit architectures. Furthermore, this frequency modulation system has superior interference resistance than phase and amplitude modulation communication, rendering it suitable for intrabody communication with dynamic physiological environments.