In this paper a novel-type beamforming network based on reconfigurable couplers is introduced. The type of reconfigurable couplers used in this paper have already been introduced by the author in a previous publication, where its capacity and potential to arbitrarily split an input signal into two signals of almost arbitrary power has been demonstrated, with very little losses. To be exact, the reconfigurable couplers used in the present paper offer a measured dynamic range of no less than 40 dB at 2.5 GHz.
Used in the configuration of a beamforming network, such reconfigurable couplers offer not only a tremendous capability to perform amplitude tapering as required by antenna array systems for a given set of radiation parameters, side lobe levels for example, but also it also has an added ability to effectively shut down antenna elements that are not in use and redistribute this power to the remaining active antennas. This is in opposition to the standard way beamforming networks are configured, where the power of the shut down elements is burnt on an absorbing resistor, which is clearly a waste of valuable resources. In the demonstrator, we deployed the proposed reconfigurable couplers and phase shifters to form a beamforming network with 16 antenna elements operating at 2.5 GHz.
Fig. 1: Top view of novel 1 to 16 beamforming network