The Research Of Tracking Radar Improved Factor Testing Equipment Based On ARM And DDS+PLL

Tracking Radar Improved Factor Testing Equipment is a type of potable equipment which has both Improved Factor testing and Radar ranging precision functions. It can be used during the testing of the functions mentioned before when producing Tracking Radar in large quantities. This equipment overcomes the shortcomings of the traditional testing method which depends on expensive meters. Also, comparing to other Improved Factor equipment, the Tracking Radar Improved Factor Testing Equipment directly uses the signal transmitted by the testing radar to keep from learning the format of the testing radar signal. This thesis mainly researches two key parts on how to implementing Improved Factor Testing Equipment: high frequency resource which bases on DDS+PLL high frequency resource and control part of a system based on ARM.As by concentrating on realize a high resolution and broad band continuous wave frequency, it makes the development, invest and function of the equipment to be balanced. At the meantime, the equipment adopted embedded ARM7 control scheme to improve the intelligence function for users having a friendly experience while using it.In research of DDS+PLL frequency resource, we mainly discuss the factors which affect the stability of PLL and give the policy that how to design Loop Filter without affecting the stability of the system. Final, we simulate the loop frequency response of open loop or closed loop by using ADS. The key part of the application of PPL is the design of loop filter. However, the calculation of loop filter constant is sophisticated and it is hard to calculation. Thus, from the principle of loop filter design, we were using ADS simulation method to get the optimized design parameters.Another major job of the thesis is developed the application programmer of control system which in the Improved Factor Testing Equipment. In order to enhance users’ experience and safer operation environment, we developed two styles of user interfaces program which are local control program based on ARM and remote control program based on LabVIEW. The control program which developed in ARM embedded system executes and calculates the input by users from local interface and remote interface as well as controls DDS, PLL and time-delay module. And we also have done the bottom level driver with control system; it’s the emphasis and difficulty of development. Development of control software based on LabVIEW, realized by software engineering methods, take full advantage of LabVIEW’s plenty of interface control module and communication function, makes the design of remote control interface to be easier. Therefore, we do not put too much effort on the description of this part in the thesis.The DDS+PLL Local oscillators and local control program based on ARM and remote control program based on LabVIEW has been applied to actual research projects, to meet the design targets, the application effect is good, the program is stable.