Universal Design Curves for Effects of Dispersion in Phased Array Radars

Wide bandwidth waveforms, providing high range resolution, are becoming increasingly prevalent with the advent of diminiscing costs for signal processing. However, phased array radars that do not incorporate time-delay steering suffer dispersion loss and pulse broadening effects from wide bandwidth waveforms. This paper presents universal design curves for quantifying the effects of dispersion in corporate-fed (equal line length) phased arrays. These curves are applicable to all shapes of aperture (linear, rectangular, oval, or circular) and to all types of waveforms (unmodulated pulses, frequency modulated, and phased coded). Conversion factors are presented to convert physical aperture size to effective aperture size for different aperture shapes and illumination functions. Similarly, conversion factors are presented for determining effective pulse length for the radar pulses whether the pulses are unmodulated, phase coded, or frequency modulated with a large spread of time-sidelobe design levels.