Wideband matching of handset antenna ports at noncontiguous frequency bands

Due to the mutual coupling between the different excited ports, designing multiple wideband matching circuits for handset antennas is not straightforward. This paper presents design principles for wideband matching circuits of two-ports and analyzes their significance in the case of multiple noncontiguous frequency bands. The proposed optimization procedure helps to design matching circuits, which may enlarge passbands, improve isolation between antenna elements, and most important, improve efficiency in the antenna design. General principles have been illustrated with examples, and also measurement results are given.