Isolation enhancement in a dual port antenna

There is currently much interest in multiport and multiple antenna systems. However, embedding many antennas closely in a printed circuit board will raise the issue of mutual coupling between them, which will decrease their performance. The research described in this paper, concerns enhancing the isolation in a dual port antenna. The general approach is to design a four-port feed network to be connected to the antenna to fulfil this task. The sample antenna that the approaches were applied to was a dual-port UWB-Narrowband antenna [1]. The feed-network that has been designed, fabricated and tested consists of a coupler and a phase shifter.