基于声表面波色散延迟线的频谱探测系统

利用声表面波(SAW)技术设计的Chirp变换频谱仪(CTS)具有低功耗、高稳定性等优势,特别适用于深空探测领域。该文提出了一种大带宽的CTS系统。由数模转换器(DAC)和四倍频器产生2 GHz带宽的展宽线Chirp信号,其色散特性与1 GHz带宽的声表面波色散延迟线特性匹配。搭建了实时处理带宽为1 GHz、频率分辨率为100 kHz的频谱分析仪,并对在大带宽下CTS出现的响应不均衡展开探讨。分析了系统各部分对CTS的影响,通过实验验证了响应不均衡出现的原因。测试结果表明,该文设计搭建的1 GHz带宽CTS系统的频率分辨率可达115.512 kHz。

Research on Spectrum Detection System Based on SAW Dispersive Delay Line

The Chirp transform spectrometer(CTS) designed using surface acoustic wave(SAW) technology has the advantages of low power consumption and high stability,and is especially suitable for the field of deep space exploration.This paper proposes a large bandwidth CTS system. A 2 GHz bandwidth Chirp signal is generated by DAC and frequency multiplier,and its dispersion characteristics match those of a 1 GHz SAW delay line.A spectrum analyzer with a real-time processing bandwidth of 1 GHz and a frequency resolution of 100 kHz is built, and the unbalanced response of the CTS under large bandwidth is discussed.The influence of each part of the system on the CTS system is analyzed,and the reasons for the unbalanced response are verified through experiments.The test results show that the designed and built CTS system with a bandwidth of 1 GHz can reach a frequency resolution of 115.512 kHz.