Multiple beam microstrip patch array with integrated beamformer

A novel antenna concept that incorporates a beamformer and radiating array into a single, planar device is described. This integration of the beamformer and array components decreases the constructional complexity considerably. The beamforming action resembles that of the Blass matrix (1960), although the use of resonant arrays removes the need for directional couplers. The devices primary mode of operation is detailed and a number of performance capabilities are outlined. Results are given for a five beam experimental array realised in microstrip and operating at approximately 8 GHz. Peak gains of between 13 and 19 dB are achieved with a bandwidth of about 5%. Implementation of the concept in other transmission media seems possible and realisation in waveguide and suspended stripline are discussed as a means of increasing efficiency.