Design of closed-loop system for micromechanical resonators based on FPGA

In this paper, an FPGA-based closed-loop control architecture is proposed to address the key issues such as slow dynamic response and insufficient frequency tracking accuracy in the research of micromechanical resonator closed-loop control systems. The system adopts a preamplifier circuit to achieve weak resonance signal extraction and combines an improved digital phase-locked loop (DPLL) with digital automatic gain control (DAGC) to form a closed-loop control. The system innovatively combines analogue signal conditioning with digital signal processing, and real-time phase detection and amplitude adjustment are implemented in FPGA through hardware description language. The test results show that the frequency accuracy reaches 99.99% and the amplitude accuracy reaches 96.97%, which meets the design requirements and lays an important foundation for the practical application of micromechanical resonators.