宽带数字接收机I/Q幅相不一致性的校正

Calibration of Amplitude and Phase Inconsistency of I/Q Channels in Wideband Digital Receiver

随着数字技术的发展,正交双通道变换在接收机中得到了广泛的应用。但是,由于各种因素的影响,I/Q通道的正交一致性并不能得到完全的保证,这会降低接收机的动态范围,进而影响接收机的性能。本文提出了一种宽带数字接收机I/Q幅相不一致性的校正方法,首先通过一种时域方法获得误差信息,接着构造滤波器组对I/Q信号进行校正。仿真结果表明,这种方法能有效提高宽带接收机I/Q通道的正交一致性。

Quadrature bi-channel transform is used widely in radar receiver along with the progress of digital technique. But I/Q mismatches are generated in this process due to diversified factors. These mismatches will limit the dynamic range of receiver, and weaken its performance. This paper proposes a calibration method of I/Q mismatches for wideband digital receiver. First, the I/Q mismatch errors are estimated in time domain by local test signal injection. Second, a set of digital filters is constructed to calibrate them. The simulation demonstrates the effect of this method.