The radiation characteristics of ultra-wideband (UWB) monopulse arrays are discussed in this paper. The UWB arrays considered here consist of ultra-wideband sources radiating coded sequences of ultra-narrow Gaussian mono-pulses with very low duty cycle. A pseudorandom (PN) time-hopping spread spectrum technique is utilized for further spreading the signal spectrum and providing multiple access interference rejection, and secure communication. Pulse position modulation (PPM) at the rate of many pulses per data bit is used for data modulation. At the receiver correlation is applied and the PN code is used to discriminate between the desired and interfering signals. A model for the general UWB monopulse volume array has been developed. Mathematical formulas for parameters of interest have been derived and computed results have been presented.