Novel method of multiplexing radiocommunication antennas using circular-array configuration

This paper describes the application of a circular array for the central antenna of base/repeater stations in mobile communication systems. The antenna is fed from a multiple-port feed network, which offers a number of electrically independent patterns which have omnidirectional coverage. The nature of the network is described showing how it can provide isolation between multiple transmitters and receivers. Experimental results are presented which suggest that 30 dB isolation can be achieved over an octave bandwidth.