Transmit Sub-Apertures for Beam Broadening and Frequency Diversity

We describe a set of techniques that make use of multiple sub-apertures transmitting multiple frequency beams which can be directed to the same or different directions. These techniques provide transmit beam broadening and frequency diversity capabilities. Processing schemes involve non-coherent integration for detection and a least squares procedure for combining multiple frequency measurements for monopulse angle estimation. Performance prediction tools are developed and evaluated for various target fluctuation models. Transmit beam broadening capabilities improve radar timelines in stressing scenarios and support multi-mission applications while frequency diversity improves search and track performance for Swerling 2 targets.