Approximating the Stretch Processor's Response to Monochromatic Interference

Stretch processing, a popular signal-processing method for modern radars using wideband linear frequency modulation, efficiently achieves fine range resolution for accurate range measurement, effective target discrimination, and high-resolution imaging. However, additive interference signals, both random and deterministic, degrade the stretch processor's performance. Through an innovative application of the principle of stationary phase, this paper derives a convenient yet accurate approximation to the stretch processor's response to a deterministic monochromatic interference signal. Favorable agreement of the derived expression's predictions with the corresponding exact responses for three example cases verifies the derived expression's correctness.