Investigation of tunable matching circuits for multiband 4G handsets

Two antenna designs with tunable matching circuits suitable for 4G mobile terminals are presented. SPDT MEMS switches and tunable capacitors as active components are evaluated in those two different antenna topologies, in scope of the Artemos European project. The target bands include the 4G communication bands, i.e. 700-960MHz as the low-band (LB) and 1.7-2.7GHz as the high-band (HB). In the first design, the antenna operates in the target bands using two SPDT MEMS switches and a two-branched matching network. The second design is a dual-feed structure, where the LB reflection coefficient is tuned using a BST capacitor while the coverage in HB is permanent.