Design of a rectangular frequency invariant beamformer with a full azimuth angle coverage

A novel design of the frequency invariant beamformer based on a rectangular array is proposed. There are two unique features about this design: there is no taped delay-line (TDL) or any other temporal processing involved and the resultant beamformer has a full 360° azimuth angle coverage. Two design examples are provided with a satisfactory frequency invariant property.