Research of Frequency Measurement Algorithm for Frequency Modulated Continuous Wave Radar

摘要

The intermediate frequency (IF) signal of the frequency modulated continuous wave (FMCW) radar is a discrete signal which is truncated by triangular wave. It has a continuous spectrum which is made up of given main wave petal and multiple side wave petal. When we make discrete Fourier transform to these signal, we can only get some discrete value of the continuous spectrum. Especially in the short distance measuring, the serious frequency leakage will happen. For the purpose of improving the measurement precision of the IF signal, this paper presents a frequency measure algorithm which combines frequency automatic tracking with spectrum correction. In order to restrain spectrum leakage, this algorithm adopts a new frequency tracking technique by fixed sampling frequency and dynamically adjusting sampling number. Afterwards, the spectrum is further corrected by ratio method. The algorithm was simulated by LabVIEW. Experimental results shows that the Frequency measure precision has improved about 60 times, and we get more anti-jamming ability.