Phase Synchronization Method for Millimeter Wave Radiometer Digital Correlator

L-band geostationary orbit millimeter-wave radiometer for meteorological disaster warning, using synthetic aperture technology and FPGA-based digital correlator to replace traditional analog correlators, has great advantages in integration, variable integration time, number of channels, etc. There are 70 antenna channels in the system, requiring a maximum integration time of 200ms. A multi-channel phase synchronization method based on phase compensation is proposed in this paper. This scheme has high flexibility and can be adapted to different front-end antenna elements. The test result shows that the phase difference between 70 channels reaches the critical index requirement of less than 100ps and has good inversion imaging effect.