采用矢量调制器实时消除模拟相关偏置

在采用模拟复相关器的综合孔径辐射计中，模拟复相关器会受到很多因素（环境温度、信号串扰等）的影响而引入随时间变化的相关偏置。引入的相关偏置对高灵敏度室内综合孔径辐射计的影响很大，实时消除相关偏置是综合孔径辐射计设计中的关键点和难点。提出了一种采用矢量调制器实时消除模拟相关偏置的算法。通过算法推导和论证，在现有综合孔径辐射计中进行了验证，很好地解决了相关偏置问题，相关偏置的残余误差可以达到5%以内，校消的速度受限于积分时间，本文可以达到毫秒量级。本文算法简单易实现，也可广泛应用于其他需要实时消除此类干扰的系统中。

Real-time elimination of analog correlator offset using vector modulator

The analog complex correlator used in aperture synthesis radiometers is easy to be affected by many complicated factors, for example ambient temperature, signal crosstalk and so on. These factors result in correlator offset value change with time, which will significantly impact the performance of aperture synthesis radiometers. Real-time elimination of the effect of complex correlator offset value is the difficult and key point in the design of aperture synthesis radiometers. In this paper, a calibration method using vector modulator is proposed to eliminate in real time the effect of complex correlator offset value. Through algorithm derivation and argumentation, the proposed method is verified in the existing aperture synthesis radiometers, and the results show that it perfectly eliminates the effect of correlator offset value. Residual offset value is less than 5%,and calibration time is limited to the integration time of complex correlator, which is mentioned in this paper is at a millisecond level. The real-time calibration method proposed in this paper is efficient and easy to implement, which can be widely used in the systems where this kind of interference needs to be eliminated.