一种ADC不同步下的数字干涉仪校正方法

A Calibration Method Based on Multi-ADC Asynchronization in Digital Interferometer System

干涉仪测向具有测向精度高、算法简单、设备量适中的优点。随着宽带高速模数转换器(Analog-to-Digital Converter,ADC)的应用,通道间多芯片ADC采集的同步越来越难实现,通道间ADC不同步导致了通道间时变的群延迟,这个不确定的群时延附加了额外的时变相位差,最终使得干涉仪应用受到了限制。针对这种ADC器件不同步的情况,提出了一种容易实现的系统校正方法,有效消除了ADC不同步的影响,取得了高精度相位差测量。

Due to the high accuracy of direction finding and simple algorithm for the engineering realization,the interferometer is widely used in the passive detection system.Along with the application of high speed analog-to-digital converter(ADC)in the digital wide band receiver,the synchronization design of multi-channel ADC is becoming more and more difficult.The asynchronization will bring the time-varying difference to the group delay of the multi-channel,which makes the phase difference become time-varying.This paper presents a calibration method for the high-precision interferometer direction finding system.It can effectively eliminate the influence from the time-varying phase difference due to the multi-ADC asynchronization,and realize the high precision measurement of phase difference.