Wavelength-scaled ultra-wide bandwidth multi-function phased arrays

The Navy has sponsored past programs designed to demonstrate that advanced, multi-function phased arrays are a feasible concept. Based on these successes, the goal of the Integrated Topside program is to improve platform capability and flexibility while greatly reducing the proliferation of topside antennas and their associated mutual interference by combining many systems (currently performed by separate antennas) into a smaller set of wideband phased-array apertures. Assuming performance metrics can be met, the limiting factor becomes cost. For satellite communications, a relatively large aperture is required to achieve a narrow beam width. Further, the element spacing of the array is dictated by the highest frequency of operation, with the overall size of the array typically dictated by the aperture requirements at the lowest frequency. This combination a large aperture for low frequencies with dense element spacing for high frequencies results in excessive element counts leading to prohibitive costs. While the cost factor is somewhat offset by the fact that several systems can be combined into a single system, in many cases the antennas being retired are relatively inexpensive reflector-based systems. However, because of the great potential benefits in driving down the number of onboard antennas and improving system flexibility, the Navy has considerable interest in reducing the cost of wideband phased-array systems.