Antenna pattern control by phase-only weighting

There has been some interest recently in beamwidth and sidelobe control using phase only weighting of phased array element excitations. This maximises the power output by setting all element amplitudes equal and incurring no taper loss in the beam forming network. To date, the approach has been to apply a phase distribution across the aperture to try and imitate conventional amplitude distributions. The paper investigates an alternative approach whereby the aperture is divided into interleaved subarrays each of which generates a separate beam in space. By directing some of these beams slightly off boresight the resultant composite beam can be controlled in terms of beamwidth and sidelobe levels