LP and CP Polarization Reconfigurable Antennas for Modern Wireless Applications

This paper will present a series of novel polarization reconfigurable antennas for modern wireless applications. First, three multi-linear polarization reconfigurable antennas with the switchable 0°, +45°, 90° and-45° polarizations are investigated for mitigating the polarization mismatching problem in wireless biomedical applications. Three distinctive techniques were adopted to realize the same reconfigurability but with different radiation performance. In the beginning, a multi-dipole structure was designed. Four switchable half-wavelength dipoles were arranged in a compact structure and fed by a same source. Later, we used the slot antenna as the basic radiating element to realize the same polarization reconfigurability but with the improved directivity. Furthermore, to reduce the profile of the previously proposed two designs, a multiple L-probes fed circular patch antenna was designed. The profile was significantly decreased but the gain was improved. Second, three circular polarization reconfigurable antennas are introduced for increasing the channel capacity in satellite applications. Initially, a wideband CP reconfigurable antenna with conical-beam pattern was realized at the first time. Later on, two wideband broadside CP reconfigurable antennas were designed. The achieved bandwidth of our proposed antennas are widest among all the previously reported works.