A Method of Phase Correction in Multichannel Channelized Receiver Based on Cubic Spline Interpolation Algorithm

The phase difference caused by the inhomogeneity and temperature drift among the channels of the hardware device and the various channels of the multichannel digital channelized receiver will cause unpredictable errors in the subsequent positioning and direction finding results. This design implements the phase alignment based on cubic spline interpolation after the digital down conversion with the multiple data collected by the AD acquisition card by the MATLAB simulation platform. Through multiple experiments, the error is within an acceptable range while ensuring that the sample size meets statistical stability. The phase need to be corrected for each path is compensated by the regenerated local oscillator data to guarantee phase difference of each channel within one degree in this paper. In the design process, the local oscillator data with phase compensation and multichannel AD data are down converted, then the cubic spline interpolation algorithm is applied for phase calibration. The experimental data shows that the phase difference of each channel is controlled within one degree. Further data analysis and experiment can measure and calculate the time base error caused by AD and source amplifier board card. This method has important reference value to calibrate the hardware equipment index.