Spectrum aggregation method for resonant MEMS micromirror-based FMCW LiDAR system: design for high-speed scanning compatibility

To address the inherent contradiction between high-speed scanning of resonant MEMS micromirrors and stable sampling of FMCW LiDAR, this paper proposes a compact system scheme integrating dedicated hardware modules. The system retains the resonant operation mode of MEMS and optimizes the signal processing chain by introducing a full-random DRAM read module and a parallel FFT module: The full-random DDR read module supports efficient caching and random access of echo signals from the same spatial point across multiple scanning cycles, providing a hardware foundation for cross-cycle signal aggregation; The parallel FFT module, implemented on FPGA, enables 4096-point real-time spectrum analysis with a sampling rate of 100MSPS, significantly improving the speed of spectrum analysis. At the hardware level, through phase locking between the biaxial electromagnetic drive circuit and laser modulation, combined with balanced detection and a high-speed ADC acquisition chain, the system achieves 100×100 resolution imaging over a 25°×36° field of view without modifying the MEMS hardware. This system balances compact design and high-precision performance, offering a cost-effective and engineering-practical FMCW LiDAR solution for scenarios such as autonomous driving and robotic perception.