The Realization And Design Of Radar Wideband Digital Receivers

The radar receiver is an important part of the radar system, its main function is tomanage the tiny signal received by the radar antenna amplification, do things like frequencyconversion, filtering, and digital processing, while suppressing the noise and clutter comefrom external interference and the noise come from the machine, keeping the signal as muchas possible of the target information for further signal processing and data processing.This paper is based on the design of the passive radar digital receiver, aspects like theselection of the digital receiver structure system, the dynamic range of design are discussed inthis paper. At last, come up with a broadband, high sensitivity, large dynamic range of thereceiver design implementations. In the design, according to the existing engineeringconditions, we come to the conclusion that if the wideband digital receiver take the RF directsampling, not only put strict requirements on the A/D speed and accuracy, more importantly,the subsequent digital signal processing and the entire system will pose a very pressure. Alsoneed to address the relationship between the performance of the system’s dynamic range andsensitivity. To solve these problems, you need to converse the signal from the receive antennareceiver to IF, and then use three different functions of the digital receiver integrated into areceiver system to the implement the receiver of broadband, high dynamic range and highsensitivity.According to design requirements of the receiver system, through the comparativeanalysis of existing analog and digital receivers, we select digital video receiver, the digital IFreceiver and digital channel receiver to compose a connected mobile phone system tocomplete the radar signal reception. Digital video receivers in the receiver system completesthe video signal sync pulse signal and the AGC control; digital IF receiver completes thedigital processing of information in the pulse to produce the I and Q signals for signalprocessing location information solver; digital channel receiver completes the solver of giventhe information in the pulse signal spectrum and give the characteristic data for signalprocessing and signal type analysis. Designed digital receiver system can be done to get thetarget and get the target location information, the complete frequency information to passed tothe signal processing work, completing the receive functions.According to the different needs of the three receiver functions and algorithms tohardware resources, this paper complements the design of three receivers respectively. Thedigital video receiver and digital IF receiver using the ADC figures of sampling adopted the method of adding FPGA to complete the hardware design; digital channel receiver are ADCfigures of sampling adopted the method of adding FPGA and DSP to complete the hardwaredesign, and critical timing and hardware selection are explained.The three kinds of fusion receiver system will take hardware debugging, veneer testingand system testing before the installation on the passive radar, in the laboratory and field testsboth meet the design requirements.