FMCW range resolution for MMW seeker applications

The power spectrum for the mixer output for a homodyne frequency-modulated carrier wave (FMCW) system with a sawtooth waveform corrupted with sinusoidal nonlinearity is presented. Since this difference or beat frequency spectrum for an FMCW radar corresponds to the return power as a function of range, the spectral width is proportional to the range resolution. This nonlinearity analysis illustrates the challenge of achieving the fine range resolution implied by the wide transmit bandwidths often used. Fine range resolution is important to seeker performance because it reduces the clutter area and clutter return power. Waveform bandwidth and range resolution, frequency sweep nonlinearities, and computational details are discussed.<>