Eigenmode decoupling of miniaturised diversity antennas using compact quasi-lumped networks

This paper investigates a three-port antenna array with an element separation of lambda/10. A compact decoupling and matching network, realised by quasi-lumped elements, compensates for the problem of mutual coupling between the radiators. One special feature of this network is the excitation of the eigenmodes of the antenna array, which results in a broad decoupling bandwidth. The physical properties of such a system as well as practical realisation strategies are discussed. Measured data are presented for the power matching and the efficiency of the system.