Beamforming Network Based on Novel Continuously Tunable Couplers

In this paper a new beamforming network for a given number of antenna elements is presented. The new architecture is capable of adaptively distributing an input RF signal among all individual antenna elements with an arbitrary selection of magnitudes and phases. The presented architecture is based on a novel coupler design, which is theoretically capable of an arbitrary division of power between its two output ports. The control of power division ratio is achieved by means of active elements capable of modulating its reactance, such as varactor diodes. As a demonstrator of the proposed beamforming concept, a feeder network for an array of 16 antenna elements is designed, simulated and fabricated to operate at a frequency of 2.5 GHz. The obtained results indicate an unprecedented level of reconfigurability, showing that the input signal can be divided among the antenna elements with arbitrary values of magnitudes and phases. The results are discussed.