An alternative approach for designing narrowband antenna array processors with broadband capability

An alternative approach to the design of narrowband antenna array processors with a specific broadband capability is presented. The approach consists of two parts. In the first part, the processor is constrained to have a unity gain in the desired look direction at the centre frequency of the frequency band of interest. In the second part, an additional set of linear constraints are used to ensure that the gradient of the response of the processor can be approximated to have a zero slope, in the minimum mean-square sense, over the frequency band of interest. Computer simulation results show that the approach is very effective for designing narrowband array processors with broadband capability. The basic approach can also be used to design broadband antenna array processors without the need of presteering time delays.