Design And Implementation Of Isar System Based On ZYNQ

Radar imaging techniques have been developed for more than 50 years. With the development and application of integrated circuits and imaging algorithms in recent years, radar imaging technology has made great achievements in defense and civilian field. It has not only improved the information acquisition ability of radar for the targets of interest, but also provided an additional way to detect the non-cooperative targets. Radar imaging technology is a milestone for radar development and a research hotspot in the field of radar. Generally speaking, imaging radar includes synthetic aperture radar (SAR) and inverse synthetic aperture radar (ISAR). Their basic principle is the same which processes echo signal of the targets both in range and azimuth direction accordingly. But in the specific imaging system, SAR takes advantage of the motion of radar platform to form a synthetic aperture imaging fixed area. However, ISAR uses the target’s motion to image itself.ZYNQ-7000 series that are launched by Xilinx have integrated the latest ARM processor and FPGA logic resources. Xilinx has also provided a lot of development tools, evaluation boards and software support packages. As a new generation of system on a programmable chip, ZYNQ-7000 can provide complete on-chip peripherals and standard interfaces through ARM processor. Besides, it can acquire high computing performance and data transmission capability via FPGA. AD9361 launched by ADI is a high performance processor which has dual transmitters and two receivers with integrated 12-bit ADC and DAC. Its operation frequency range is 70MHz-6GHz which covers the unlicensed bands used in a number of protocols and some other available spectrum. Therefore it has a wide range of application. The chip also has a lot of advantages, such as real-time monitoring, automatic gain control, high receiving sensitivity, control flexibility, low power consumption, and so on.In this paper, the design scheme and implementation method of ISAR system based on ZYNQ and AD9361 were studied. In the hardware system, first, the ISAR imaging theory and common algorithm were in-depth analyzed. Then, according to the demand of the signal source of ISAR signal processing, I designed the system frame, planned the function of every module and researched the evaluation board’s performance. At last, I designed a hardware solution based on ZYNQ and AD9361 to achieve the ISAR system. In terms of system software, firstly I have carefully analyzed some driving methods of all kinds of evaluation boards which are recommended by Xilinx and ADI. Then, considering the existing conditions, Based on Matlab and Xilinx providing SDK control software was designed and implemented to drive the system to accomplish the signal transceiver and echo data’s storage.To verify the system function, two tests have been performed on the underlying hardware, including whether the signal can be sent and received successfully and what the maximum signal bandwidth of the system can normally work is. Finally, the whole system is deployed in two different real scenarios, and the observed echo data are dealt with by the ISAR algorithm. The experimental results have verified the feasibility of the system, showing that it can accomplish the acquisition of target information.