Optimization of Modulating Waveforms for maximum Signal-to-Noise Ratio In a FMCW Radar

This work presents an analysis of the received intermediate frequency (IF) spectrum for various modulating waveforms in a frequency-modulated continuous-wave (FMCW) radar system. Each waveform generates its own distinct IF spectrum, even when other parameters are held constant. The spectrum is additionally influenced by the sampling rate and the sampling window applied for the FFT operations. Four widely used waveforms-sinusoidal, sawtooth, triangular, and square waves, are considered for range measurement. The theoretical analysis shows that the sawtooth waveform produces the highest peak-to-peak voltage at the fundamental beat frequency. Therefore, it enhances the accuracy of range measurements. The theoretical predictions are validated through experiments conducted on an in-house built FMCW radar circuit.