One-element diversity antenna with reactance-switching circuit for mobile phones

We have proposed a novel type of diversity antenna construction for compact mobile telephones. The proposed diversity antenna basically consists of one excitation element, the conducting-plate, and the reactance-switching circuit connecting between the end of the element and the conducting-plate, and need not install two excitation elements. We have demonstrated numerically and experimentally that the current phase distribution and radiation pattern can be controlled by appropriately switching the reactance value of the reactance-switching circuit. Our next works are to establish an optimum design theory and to investigate the performance in talking and browsing situations.