Arraying high gain antennas

In some applications, coherently combined multiple antennas are more appropriate than a single larger antenna. Coherent combining produces grating lobes, and one of these lobes must be aligned with the signal. Narrow bandwidth applications use phase shifters for coherent combining, but true time delay compensation is required to maintain combining efficiency over the bandwidth for wide bandwidth applications. Efficient techniques using phase shifter/true time delay combining for aligning the grating lobe peak with the signal are described.