Design And FPGA Realization Of The Multi-function Signal Generator

Signal source is a basic and widely applied electronic device.It can provide standard signals for some devices which need to be measured and it has a very important position in modern electronic technology.Link11 data link is one of the most widely used general data links,which has the characteristics of real-time information transmission,diversified combat unit interconnection and so on.This dissertation combined the XXX project cooperated with a research institute of China Electronics Technology Group Corporation and a set of multi-function signal source system is designed,including the general signal source and Link11 data link part,and FPGA is used to realize the digitalization of signal source.The main contents of this dissertation are as follows:The basic principleof modulation about the general signal sourceis expoundedand the realization process of fixed frequency,spread spectrum and frequency hopping in detail are analyzed.Put forward a design method which the input signal is adjustable frequency from 10 kHz to 5MHz of 1kHzstep with high precision and small error and the range of intermediate frequency is from 215 MHz to 235 MHz with 1kHzstep based on project.The system structure of Link11 data linkis analyzedand the single tone modulation technology is introduced.The three message formats and the frame structure are analyzedincludingnetwork control station call message format,outpost response message format and Network control station report message format in polling mode.The key technologies of digital implementation of multi-function signal source and Link11 data link are studyed and realized,including DDS and the reshaping filters.The principle of of?/4-DQPSKis analyzedbased on the simulation.The modules of the general signal source and Link11 data link are establishedin Quartus II software and doing function simulation to verify the correctness.The hardware applies the FPGA and AD9957 cascaded,baseband is processed in FPGA,up-conversion is processed in AD9957.The downlaoading of program and outputting of signal are realized in the system hardwareplatform.Testing the performance index of each signal including error vector magnitudevia VSA from vector signal analyzerto verify the index satisfying the demand or not.