Simulation And Rearch On The If Signal Process Of High Performance Spectrum Analyzer

The Spectrum Analyzer is a common measurement instrument in modern RF and microwave field. With the development of the technologies of micro-electronics, computer and digital signal processing,the technique of frequency spectrum analysis has had profound changes.To make it be realized by softwares and digital is a trend for spectrum analysis.Digital IF signal Proeessing is one o fthe key techniques of spectrum analyzer. Digital IF processing is the process that RF analog signal is changed into digital signal,then become to base band signal through DDC and digital filters.there have specrum analysis on base band signal.This method of spectrum analysis is used rapidly and efficiently.This thesis has emphasized on the IF Signal Process in the high Performance Spectrum Analyzer. Firstly,this paper introduces the working principle of the spectrum analyzer and spectrum analyzer technical performance indicators, and demonstrates the use of digital IF signal processing technology superheterodyne spectrum analyzer advantages.Then,the rationale of the digital IF processing technology,which contians the bandpass sampling theory , an integer multiple of extraction,digital filter,mixing technology,is introduced. Focused study of the digital IF signal processing due to sampling, anti-aliasing filter, DDC, multi-rate decimation filter (CIC filter, half-band filter), FIR shaping filter and a series of key technologies , for each module which carried out a detailed analysis of the principle. Then using the ADS and MATLAB software for each module (anti-aliasing filter, digital-(ADC), digital controlled oscillator (NCO), digital down converter (DDC), multi-rate decimation filter (CIC filter, half-band filter), FIR shaping filter) provides a detailed simulation modeling, and gives key modules of the design schematics and simulation results. Finally, high-performance spectrum analysis all-digital IF signal processing system, the impact of IF filters on the resolution, and gives experimental results. Studied in this paper a high-performance spectrum analyzer, digital IF signal processing techniques, but for us to track foreign electronic test technology and new developments in spectrum analyzer will be used to better scientific research and experiments have important practical significance.