| The essence of stealth technology is to achieve stealth by reducing the target’s radar scattering cross-sectional area(RCS).Developing to higher frequencies is one trend of antistealth radar.The D-band radar sensor operates at 110 GHz to 170 GHz and is located at the low end of the THz.It belongs to the millimeter wave radar too.Modern stealth aircraft are mostly designed for centimeter-wave radar.Therefore,under the irradiation of D-band electromagnetic signals,each fine structure on the surface of the aircraft can be regarded as a scattering point,so the RCS value of the stealth aircraft is increased.Based on a radio anti-stealth near-field detection technology project for air targets,a D-band LFMCW system real-aperture imaging radar signal processor is designed and implement in this thesis.Also,software related to the design and debugging of signal processing is completed.The content of this thesis mainly includes the following aspects:1.A real-aperture two-dimensional imaging scheme based on the D-band LFMCW system is designed.Through the design of LFMCW transmission waveform,the design of threechannel virtual baseline phase interferometer and the design of signal processing algorithm,two-dimensional imaging of the real aperture of the air target is realized.The detection performance is analyzed through simulation.2.According to the requirements of the designed real-aperture two-dimensional imaging scheme,a signal processor hardware circuit for the D-band LFMCW system real-aperture imaging radar was developed,and the schematic design of the circuit and the processing and welding of the PCB were completed.At the same time,the design of the hardware circuit of the intermediate frequency local oscillator frequency source has also been completed.3.The software design of real aperture two-dimensional imaging signal processing is completed on the radar signal processor hardware,including three-channel high-speed A/D sampling software design,high-performance FPGA and DSP signal processing software design,and high-speed serial interface software design.At the same time,the software design of the intermediate frequency LFMCW waveform generation was completed on the frequency source hardware.4.Completed the LFMCW waveform generation test of the frequency source circuit,the three-channel intermediate frequency sampling and channel phase calibration test of the radar signal processor,the signal processing test of the radar signal processor hardware,and the realaperture two-dimensional imaging test.The results of the test verified the correctness and effectiveness of the software and hardware design of the signal processor. |
