Three Mm Band High Linearity Of Frequency-modulated Continuous Wave Source

The introduction of the principle, characteristics and development of LFMCW radar in China and other countries is presented. Then, the relation between the frequency modulation linearity and the radar range resolution of LFMCW radar and a correction algorithm of linearity for LFMCW signals are discussed in detail. Based on that, the software and hardware of the correction system of linearity about 3mm LFMCW radar are designed.A digital real-time closed-loop correction algorithm of linearity scheme is simulated with the Max+plusII. It shows that the digital algorithm has the advantage of real-time, stability and higher linearity. An analog closed-loop correction algorithm of linearity scheme is simulated with the Systemview. It shows that the analog closed-loop algorithm is simple and can be easing realized. Compared with the analog opened-loop correction algorithm, the analog closed-loop algorithm has advantage of real-time and higher linearity.The program of the digital real-time closed-loop correction algorithm is designed with the VHDL language and simulated. It showed, with the FPGA chip the linearity can reach 4.1/10000.At last, the key circuits are analyzed and designed for the analog closed-loop algorithm, which provides the technology basis for a high linearity millimeter wave LFMCW signal source.