Design And Application Of 60MHz~3GHz Broadband Receiver

At present,wireless communication technology is developing rapidly,the signal form is becoming more and more complex,and the wireless spectrum is disorderly and crowded.This phenomenon not only affects the receiving and detecting of signals by the receiving system,but also makes it difficult to receive long-distance weak signals or transient burst signals.In order to improve the anti-interference ability of the receiving system and the real-time fast spectrum analysis capability,this thesis design a wideband receiver system of 60MHz~3GHz and carried out the following research work:First of all,when the signal is monitored,the system will be affected by a variety of electromagnetic interference signals.In order to solve the problem of strong interference,the subject puts forward a high-selective signal pre-selection scheme in the system design of the receiving front-end circuit.The scheme greatly reduces the interference level of the receiving front end by the cooperation of the variable frequency electric tuning filter,effectively avoids the problems of image interference,intermodulation interference,etc.,and achieves low insertion loss and high selectivity.In the design of the receiving circuit,the signal band division and the secondary frequency conversion processing are adopted,thereby effectively widening the frequency band range received by the system.Secondly,the research and improvement of the algorithm for spectrum analysis in the receiving system are carried out.The spectrum analysis function in the system is realized by two algorithms.The FFT algorithm is the spectrum calculation for the full frequency band,and the Zoom FFT algorithm can select and amplify an abnormality in the full frequency band or the frequency band that needs to be refined,and the spectrum analysis result after the selected band is more accurate and detailed.As the Zoom FFT algorithm doesn't reach the most simplified calculation,the design optimize and improve for the Zoom FFT algorithm.The optimized Zoom FFT algorithm will preferentially perform signal filtering,extraction and other processing in the calculation process,and the frequency shift calculation is reasonably set.Through the simulation platform verification,the optimized design can effectively reduce the amount of calculation,increase the calculation speed,and at the same time improve the accuracy of spectrum analysis.The receiver has high sensitivity,wide frequency band,large dynamic range,and strong anti-interference ability.It can not only play a major role in the field of wireless measurement,but also can be used in radar,remote sensing,channel measurement of communication systems,etc.,and has broad application prospects.