Study On Intermediate Frequency Signal Processing Technology Of High Altitude Meteorological Detection Receiver

In recent years, the typhoon, rainstorm and other extreme weather have a significant impact on social economy, which attract widespread attention. It is particularly important that researching on meteorological observation technology. Atmosphere aloft observation is one of the central means of meteorological forecast, and the intermediate frequency digital receiver is an important component of radiosonde system. In this paper, based on software radio, the intermediate frequency signal processing technology has been researched, intermediate frequency digital receiver which according to the system of meteorological sounding wireless data transmission has been designed, finally, actual production with performance data has been completed.Firstly, the overall program of IF digital receiver system has been researched, designed and simulated, including whole system structure and each module. After doing the analysis of a number of key technologies on intermediate frequency signal processing, with the simulation calculation, this article studies the design scheme of each module that the analog-to-digital conversion(ADC), numerical control oscillator(NCO), orthogonal mixing module, multistage sampling filter.Secondly, in the MATLAB/Simulink enviroriment, using the System Generator to implement an algorithm modeling and simulation, with the aid of ModelSim simulation tools to verify the validity of the design. This method provides the project in experimental subject the possibility of a FPGA development, greatly shorten the design cycle.Finally, based on ASIC(Application Specific Integrated Circuit), the high speed AD chip and special programmable digital downconverter are selected and analyzed about structure performance,and then the peripheral interface circuit is designed. The schematic of the various modules are designed by Altium Designer software and finished hardware circuit of the system, laying the foundation for following products development.