Joint RF-feeder network and digital beamformer design for cellular base-station antennas

In this paper a convex optimization based algorithm and architecture to design generic antenna feeder networks (AFN) for active phased arrays is proposed. The challenges are to keep the number of transceivers (cost) to a minimum, while maintaining the required beam quality. The AFN design optimizes the network at several levels: it determines the minimum number of transceivers and minimum antenna array elements to achieve a set of performance requirements such as scan angle, main-lobe and side lobe power levels (SLL), insertion loss and PA requirements. Based on this optimal algorithm a feeder network for a 2.6GHz LTE base station array is designed using a bank of power dividers, directional couplers and micro-strip lines.