Model And Simulation Of LFMCW THz Imaging System Based On FPGA

This paper uses continuous terahertz imaging technology to design a linear frequencymodulation continuous wave (LFMCW) radar system, and applies System Generator tosimulate and design the system based on FPGA. By comparing with the advantages anddisadvantages of the continuous terahertz imaging technology and the pulse imagingtechnology, we select the first technology which can obtain the contour information of themeasured object because of the simple structure and low cost. Under the guidance ofLFMCW radar mechanism, we use the " Beat-Fourier " structure to design the radar receiverand adopt the sawtooth wave to modulate the terahertz signal. According to the theoreticalderivation, the beat signals() can be obtained by the mixing processing of the echosignal,which is reflected by the measured object, and the intrinsic signal. The frequency ofis only related to the distance(R) of the measured object. The frequency spectrumdistribution of can be obtained by sampling the signal and using FFT transform. Thefrequency of can be used to calculate the distance of the measured object, and the grayinformation can be obtained by the gray quantization value which is attained by comparingthe amplitude of with the calibration value. In the Matlab/Simulink environment, we useSystem Generator for DSP FPGA modulation development tools to analyze, design andsimulate each model which can be implemented by using FPGA in the system architecture.The correctness of the design can be verified by downloading the hardware simulation modelto the FPGA development board to co-simulate.