极化雷达目标射频信号仿真精度的分析

Analysis of the Simulation Accuracy of the RF Signal of the Polarization Radar Target

在雷达目标信号优化的研究中,射频系统的幅相不一致将会影响雷达目标极化信号的精度。由于系统幅相特性的相互制约,很难建立一个统一的幅相误差模型。为提高射频仿真的可靠性,提出建立幅度和相位的误差模型,并针对极化信号的三种形式,通过理论推导与数学仿真,对幅相不一致性给极化信号仿真带来的精度影响进行分析。结果表明,相位不一致使线极化信号和圆极化信号畸变为椭圆极化信号;幅度不一致使线极化信号产生倾角误差,使圆极化信号畸变为椭圆极化信号。因此,必须提高通道间的幅相一致性才可以保证雷达目标极化射频信号的仿真精度。

In the radio frequency simulation, amplitude-phase mismatch will influence the polarimetric signal precision of radar target. This analysis can improve the reliability of RF simulation. Due to mutual restraint of system amplitude and phase characteristics, it is difficult to establish a unified model of amplitude and phase. Thus, the error models of amplitude and phase are established respectively. Aimed at the three kinds of polarimetric signals, the precision influence of polarimetric signal bought by amplitude-phase mismatch is analyzed. The results show that, phase mismatch distorts linear and circular polarimetric signal to elliptical polarimetrie signal. Amplitude mismatch will cause dip angle error of linear polarimetric signal, distorts circular polarimetric signal to elliptical polarimetric signal. Therefore, we must improve the amplitude and phase coherence between channels to guarantee the simulation accuracy of the polarized RF signals of radar target.