A Tunable Decoupling and Matching Concept for Compact Mobile Terminal Antennas

This paper presents a tunable decoupling and matching concept for compact multielement mobile terminal antennas. Instead of optimizing the antenna structure itself to achieve this purpose, the antenna elements are designed to be generic, small and placed closely to each other. The potential of reconfigurable decoupling and matching of such an antenna system, purely controlled by tunable decoupling and matching networks, is studied. The concept is evaluated by different classes of examples. First, fundamental aspects of decoupling and matching are discussed on the basis of several generic antenna matrices. Thereafter, a three-element antenna system of a mobile terminal is investigated by numerical simulations to calculate the achievable bandwidth of each tuning. This study is concluded by presenting efficiency measurements of a lab mock-up of a two-element mobile terminal antenna.