The Design And Implementation Of Broadband DRFM System

Modern electronic warfare prompted the development of DRFM (digital radiofrequency memory) technology. In order to achieve effective interference to the target,DRFM have a high speed data sampling, storaging and accurate reconstruction. Atpresent, it has been able to adapt to interference in a rapid changeable and complexenvironment. Because of the high coherence between the signal and the interferencesignal, the DRFM is widely used in military radar systems. With the development ofintegrated circuits, DRFM technology is also undergoing continuous improvement. Inorder to meet the requirement of advanced radar systems, the broadband DRFM systemdevelopment has become the urgent matter.Based on the principle of DRFM and the existing technology, this paper make aresearch and improvement to the traditional DRFM system, and design a set ofbroadband DRFM as well. The broadband DRFM system regards the high-performanceFPGA as a core, with a ADC and a DAC sampling and reconstruction. Compared withthe previous sysytem, it has some breakthrough and innovation in the bandwidth. Themain work is as follows:First of all, according to the requirement, develop the design scheme of thebroadband DRFM system, In order to satisfy the demand of high-speed data sampling,select a appropriate FPGA as the signal processing chip, determine the core of the system,then complete the design of high-speed ADC/DAC and peripheral circuit In theschematic design, considering the feasibility of the system, it has carried on thesimulation test to power management module, and the simulation results show that thedesign of the module can meet the experimental requirements.Secondly, design the PCB board. Through the reasonable design of stack and tracerules, the PCB board can achieve a best matching impedance, and enable the high speedsignal transmit effectively. Considering the electromagnetic characteristics at the sametime, the paper take the corresponding measures to suppress the electromagnetic radiation,such as the design of serpentine routing and effective grounding, etc. Finally, set up the system test platform for debugging and testing. Compared totraditional below1GHz bandwidth DRFM, the results show that the1.2GHz signal canbe achieved70dBc under the4.8GHz frequency sampling by ADC, and65dBc by DAC.Thus, the system of the broadband DRFM has basically meet the requirements of theapplication, and can complete simulation of radar echo signal in some aspect, so it hascertain significance for engineering applications.