星载SAR二维AGC的FPGA实现

FPGA Implementation of Two-Dimensional AGC for Spaceborne SAR

阐述了一种适合于合成孔径雷达(SAR)接收机自动增益控制(AGC)的方法。该方法通过对AGC起控点设定上下两个门限,用采样数据的幅度统计均值与这两个门限比较,并通过逐次步进的方法得到接收机的增益控制量,从而使AGC环路收敛,不产生振荡。同时设计采用了二维AGC,既保留SAR图像中的对比度,又提高了接收机的动态范围。最后分析了由二维AGC所引起的视频信号毛刺对SAR图像的影响并给出了二维AGC的FP-GA实现方案。实验证明,本文基于FPGA的二维数字AGC技术具有调节方便、反馈快捷和精度高的优点。

A method of automatic gain control （AGC） for synthetic aperture radar（SAR） is described. In order to assure the convergence of AGC without fluctuation, double-threshold for AGC take-over point is set. By computing the mean of acquisition data and its comparison with thresholds, the the properties o The FPGA brought by gain of the receive f SAR image are implementation for th r can be set. And the 2 kept and the dynamic e 2-D AGC and the in D AGC is adopted in the design, thus range of the receiver is also widened. fluence of disturbance for SAR image the 2-D AGC are introduced. The experiment proves that the FPGA implementation has the merits of flexibility, convergence and accuracy.