合成孔径辐射计多路高阶数字复相关器方案研究

Research on Multi-Elements and Multi-Levels Digital Complex-Correlator of Synthetic Aperture Radiometer

本文针对目前合成孔径辐射计中存在的相关器单元过于复杂 ,难以星载应用的问题 ,提出了一种新的数字相关方法 .借鉴了软件无线电中的数字接收机技术 ,利用大规模可编程门阵列 (FPGA) ,用一块芯片来实现功率分配和大量复相关器的工作 ,实现了片上系统 (SOC) ,解决了多天线单元合成孔径辐射计相关器系统中存在的体积、重量、功耗和硬件复杂程度过大的问题 .通过仿真表明 ,多路高阶数字相关器系统得到的天线阵列的干涉方向图与模拟相关器系统得到的干涉方向图基本一致 。

This paper is focused on the problem that the analog correlator unit of synthetic aperture radiometer is becoming too complex, so that it has an inverse effect on the implementation of spaceborne synthetic aperture radiometer. There is a digital correlator, which uses the technology of digital receiver that is used in soft radio. Due to the fact that the digital correlators are realized with the help of analog-digital converter (ADC) chips and the FPGA technology, the realized volume, mass, power consumption and complexity turn out to be greatly reduced compared with those of the analog correlators. Simulations show that the resolution of ADC has an influence on the synthesized antenna patterns, but this can be neglected if more than 2 bits are used.