用于深空探测的400 MHz带宽Chirp变换谱分析仪的设计与实现

Chirp变换频谱仪（CTS）具有低功耗、高稳定性等优点，在深空探测领域中具有独特的优势。罗塞塔（Rosetta）彗星探测器搭载的180 MHz带宽Chirp变换频谱分析仪，是迄今为止唯一成功完成空间任务的后端外差式实时频谱分析仪。基于Chirp变换谱分析的原理，设计构建了数字展宽线技术与声表面波压缩线技术相结合的400 MHz带宽Chirp变换谱分析仪。完成了数字展宽线与模拟声表面波压缩线的优化匹配设计，使系统的分辨率达到了理论值100 kHz。进一步采用调频信号和多频率点信号对CTS系统进行了测试验证。 

High Resolution Design and Realization of 400 MHz Bandwidth Surface Acoustic Wave Chirp Transform Spectrum Analyzer for Deep Space Exploration

Chirp Transform Spectrum analyzer (CTS) has the advantages of low power consumption and high stability, and has unique advantages in deep space exploration. The 180 MHz bandwidth chirp transform spectrum analyzer mounted on the Rosetta comet detector is the only back-end heterodyne real-time spectrum analyzer that has successfully completed space missions so far. Based on the principle of chirp transform spectrum analysis, a 400 MHz bandwidth Chirp transform spectrum analyzer was designed and built by combining the digital expander technology with the Surface Acoustic Wave (SAW) compressor technology. By analyzing the compression results in the frequency band, the phase difference between the expander and the compressor was introduced as an important factor affecting the compression waveform. According to the two key parameters of the pulse compression waveform, the main lobe width and the peak side lobe ratio, the optimal matching design of the digital expander and the analog SAW compressor are completed. The compression result of the system is optimized, so that the resolution of the system reaches the theoretical value of 100 kHz. FM signal and multi-frequency signal are used to test and verify the CTS system.