Range Resolution Improvement of a 24 GHz ISM Band Pulse Radar—A Feasibility Study

An approach to improve the range resolution of a 24-GHz industrial, scientific, and medical (ISM) band pulse radar is presented for the automotive short-range radars. The resolution of the range profile was improved by applying the regularized least squares method to a discrete baseband signal at the receiver. For a 24-GHz ISM band pulse radar adopting a regularized least square method, a triangular pulse was identified as the optimal pulse shape under the regulations and in terms of cost effectiveness. To resolve multiple adjacent pulses with a constant false alarm rate, MATLAB simulations based on the least absolute shrinkage and selection operator (LASSO) algorithm were used to derive additional threshold values for output signals after the LASSO operation and the required signal-to-noise ratio (SNR). The simulated and measured values of the required SNR were 20.5 and 21.1 dB, respectively, for the two-target detection with a range resolution of 30 cm, at the detection and false alarm probabilities of 0.9 and 10^-3, respectively.