Design And Realization Of A Doppler Radar Echo Signal Simulator

Aiming at higher and higher demand of military hardware,Doppler Radar matched with a certain type of missile is proposed a higher degree of accuracy for testing speeds.With the developments of product technology the requirement of product testing is also varied.State-run factory has designed the echo Signal Simulator according to the testing demand for Doppler Radar.The echo Signal Simulator Signal Simulator of Doppler Radar has become a necessary testing equipment for the Doppler Radar testing system due to its advantages of flexibility,economy and repetition of the echo Signal Simulator,The testing instrument for the echo Signal Simulator of Doppler Radar is mainly used for imitating to produce Doppler frequency shifts and modulate them to the middle frequency of the signal which is sent by Radar after frequency conversion.The echo Signal Simulator offers accurate measurements by imitating the real flight of Radar.It is made by choice delay,power control and other function choices after the echo Signal Simulator makes the signal frequency re-converted.The basic conception and theory of Doppler Radar is firstly introduced and the features of echo signal frequency spectrum are analyzed and calculated in this essay.Secondly it is achieved by the analysis and design for the different parts of Doppler radar echo Signal Simulator including radio frequency interconnection module,frequency conversion electric circuit,delay module,power control module,electric source module,soft ware design and so on.The overall realizing program of Doppler Radar echo Signal Simulator is briefly introduced and then the methods of realizing program for the different parts are introduced entirely,The features of the echo Signal Simulator are as the following.1.The past Doppler Radar testing and measuring instrument imitates the frequency shift signal from the middle frequency and can only cover the testing of middle frequency and back port.While the present echo Signal Simulator can imitate the echo signal from the radio frequency port,test the flexibility of the radio frequency and cover all the testing requirements of the whole radar.2.It offers non-touched testing and the all round testing is completed when the content of the radar is not exposed.3.The four-wave beam signals of the radar can be received by closed cavity coupler.The sticky abstracting materials in the coupler can effectively restrain the signal diffuse reflection of Doppler Radar.It improves the capacity of resisting disturbance and ensures the testability of the radar.4.Frequency conversion module produces 955MHz+fd signal,whose frequency precision accuracy is 1Hz,when it is controlled by the standard RS232 serial port.The Doppler frequency shift signal can be dynamically changed by standard soft ware controlling device DDS and then it can imitate the radio frequency echo signal of a simulated radar real time.It offers a new thinking and a fresh method of the simulated dynamic testing for radars.5.It is connected with radars by the mean of 1553B bus communication.It dispatches the bus data by imitating BC as PC port module and also imitates other facilities to send and receive radar data among MT.1553B bus communication is achieved by being matched with the corresponding hard ware resources after thorough and complete analysis of the contents of the agreement.The realized design of the echo Signal Simulator is tested,which is involved in five projects.The test meets with the normalized requirements and testifies the accuracy testing and flexibility testing of the radar in mass production simultaneously.The tested precision is similar to the actual flight precision.