Frequency estimator to improve short range accuracy in FMCW radar

Frequency Modulated Continuous Wave (FMCW) radars have been widely used for short and medium range detection. Applications of FMCW radar, where measuring short distances is critical, need to have a high accuracy. In the FMCW radar systems, the received signal is a delayed version of the transmitted signal. The range is calculated by measuring the beat frequency of the received signal. The range resolution of radar is inversely proportional to the transmitting bandwidth of the radar. In order to achieve a better range resolution we need to increase the bandwidth, which has its own limitations. To increase the bin resolution of FFT of the beat signal, the sampling frequency must be increased which increases the system complexity. A frequency estimator is implemented to enhance the accuracy of short range detection in FMCW radar without increasing the bandwidth or sampling frequency of the system. It compensates the error by calculating an offset value to provide fine beat frequency.