Research And Implementation Of Microwave Radiometer IF Analog System Based On Chirp Transform

With the development of space science and technology,microwave remote sensing is playing an increasing role in national economy and security.As one of the main microwave remote sensing instruments,Microwave radiometer plays an important role in microwave remote sensing system.Therefore,the study of ultra-wideband,multi-band,high-frequency resolution microwave radiometer is of great significance for enhancing the research and application ability of microwave remote sensing instruments and improving the level of microwave remote sensing detection.Microwave radiometer based on Chirp transform is a new way for implementation of microwave radionmeter.It has the characteristics of low power consumption,high stability and high precision.It can transform signal from time domain to frequency domain efficiently,thus completing the spectrum measurement of signal.The CTS architecture based on the new digital algorithm is determined by consulting the literature of CTS microwave radiometer at home and abroad and combining with the actual needs of this subject.Among them,The IF analog system is an important part of CTS system,which is mainly composed of mixer,amplifier,filter,equalizer,attenuator,signal source,etc.It mainly realizes the functions of spectrum shifting,amplification,filtering and amplitude equalization.The main work of this paper is as follows:1.According to the requirement of digital algorithm,the high spurious suppression of CTS system is realized by spectrum planning and filters;2.The basic framework of CTS IF analog system is analyzed and designed,and the CTS IF analog platform is built to verify the key issues in the system scheme;3.According to the performance requirements of CTS IF simulation system,the integration scheme and related functional modules of CTS IF simulation system are determined,and the flatness of CTS system is optimized by flatness simulation and equalizer;4.In board level,the layer structure?impedence matching and SMA joint are optimized through Cadence?CST and ADS,and the EMC and shielding cavity design of the system is completed by CST;5.The CTS IF simulation system is measured,the test results are analyzed,and the improvement direction of the system is put forward.