Compact 24GHz FMCW Automotive Anti-collision Radar

With the development of microwave techniques and the requirements of auto safety, automotive anti-collision radar has been widely studied recently. How to reduce the incidence of traffic accidents has become an extensive concern, and safety issue becomes the primary consideration of consumers when purchasing a car.The thesis aims at designing a compact 24GHz frequency modulated continuous wave (FMCW) microwave automotive anti-collision radar with miniature size of 13.5cm×12.7cm×5.5cm. We first introduce the principle of FMCW microwave radar system, along with the required performance and system parameters in the design. Then the detailed description of transmitter design, receiver design and FPGA hardware realization of digital signal processing are presented. To combat the nonlinear effects of VCO, the transmitter part contains a digital temperature-compensation VCO correction module. The onboard test shows that the nonlinearity is less than 5% after using this module. In the receiver, we design the IF circuit that matches the parameters of the whole radar system. The IF circuit path is formed by preamplifier, high-pass filter (HPF), auto-gain amplifier and analog-to-digital conversion (ADC) with the total gain of 120dB, dynamic range of 80dB. The measurement in playground confirms the IF circuit can work effectively and the data form Chipscope can clearly see the target peak in frequency domain. The FPGA implementation of detecting the distance and speed of radar target is presented. We designed a mutilate circle-difference clap-Fourier transform-MTI method for detecting the multi-targets. We design and implement the whole digital signal processing module with a Spartan-3 XC3S1500 FPGA, and through a LCD the target distance, speed and intermediate frequency information are displayed.