微波辐射谱分析仪是具有精细频谱分析能力的微波辐射计，是近年来被动微波遥感器的技术发展方向之一。本文提出的微波辐射数字谱分析系统基于快速傅里叶变换(FFT)算法，硬件平台基于Xilinx 公司7 系列下带有4 DPS 高速模拟子卡的Kintex7-FPGA 评估开发套件，实现一个输入带宽250 MHz，探测通道数16 384，频谱分辨力15 kHz，可实时观测的微波辐射数字谱分析系统。给出了系统的电路原理设计、关键模块的设计框图及软件流程图。最后将设计的Modelsim仿真结果和MATLAB 仿真结果作对比，验证了整个设计的正确性。

The radiometer with spectrum analysis backend can be considered prototypical for spectrometer development for future radio astronomical applications. This paper focuses on the design and implementation of a Fast Fourier Transform(FFT) spectrum analysis backend for radiometer. The Kintex-7 family evaluation Field Programmable Gate Array(FPGA) of Xilinx Company with a 4 DSP FMC150 daughter card is the core to complete this system. The spectrometer works continuously and has a total bandwidth of 250 MHz，resolved into 16 384 channels with a frequency resolution of 15 kHz. The design scheme of delay-calibration for high speed data transmitting，pipelined, streaming I/O FFT structure，and spectrum accumulation modules，as well as software flowchart is presented. Finally, both simulation results obtained by Modelsim and MATLAB are compared to verify this system.