Pulse width considerations for a short range millimeter wave radar

Simple means for optimizing the pulse width of a basic tracking short-range millimeter wave radar are shown. Ground-based or maritime use is assumed. The cases discussed include volume clutter due to rain or other particles within the antenna´s main beam and surface clutter due to grass, soil, or snow. Depending on the available RF hardware and desired lowest detectable target RCS, pulses as short as 20 ns look feasible. Modern signal processing methods enable the detection of targets close to the noise limit. It seems, therefore, appropriate to discuss the relevance of using 3 dB beamwidths for clutter cell calculations. Experiments suggest that more accurate predictions are obtained by using 1 dB widths instead. The lack of comprehensive data for very small grazing angles and the less surveyed small-scale topography of radar environments set some constraints for straightforward implementations. Preliminary results indicate averaged surface clutter RCS levels less than -12 dBsm at V-band for small grazing angles.