Array beam patterns of UWB-throb signals with random-throb rate

An ultrawideband (UWB)-throb signal is composed of a large number of extremely narrow pulses and characterized by pulse repetition frequency (PRF) that is a linear function of time. The design of the UWB-throb signal and its applications for high-resolution radar have been recently introduced in the radar literature. In this paper, we present the principle of space-time array processing based on UWB-throb signals with nonlinear-random PRF, or random-throb rate. The space-time resolution function for the randomly-throbbing UWB signal is derived and used to obtain the array factor and the signal-temporal profile for different design parameters. The distinguishable features of the array factor are a narrow mainlobe and very low level sidelobes. The beamwidth of the array factor is a decreasing function of signal bandwidth and array size. The structure of the signal-temporal profile, referred to as the temporal resolution function, is affected only by a change in signal duty cycle or throb rate. Such features are attractive for high-resolution imaging UWB radar.