Small-sized metamaterial feeding system combined polarization-reconfigurable antenna

This paper presents the design of a palm-sized metamaterial antenna system having reconfigurable polarization as well as dual-band characteristics. Basically, three antennas are laid by 45 degrees in order and excited by a compact metamaterial equal-ratio and equal-phase power-splitter, and the radiated fields of the antennas are mixed to turn the vector of the polarization to another. The legitimacy of the proposed method is examined by observing the in-phase outputs from the odd-numbered power-dividing device for both 900 MHz and 2.4 GHz, and checking the changeable polarization with the antenna gain over 2 dBi for all the polarizations.