Polarization reconfigurable multi-slot antenna for body-centric wireless communication system

This paper introduces a polarization reconfigurable antenna with multiple slot radiators for body-centric wireless communication system (BWCS). The proposed multi-slot antenna generates switchable 0°, +45°, 90° and -45° linear polarizations to overcome multi-path distortion and polarization mismatching in the communication environment with complex wireless channels as BWCS. To realize this reconfigurable characteristic, we combined four slot radiators together with 450 rotation between the neighboring slots. All the slot radiators share the same excitation source. By adopting PIN diodes as RF switches to reconfigure the current path on the slots, we can control a selected slot to be operated. As the result, four polarizations can be altered correspondingly to different operating slots. Experimental results show the proposed antenna with desirable electrical characteristics for all operating modes such as wideband, stable & high gain, cardioid-shaped radiation patterns. We also conducted the communication link measurement between an implantable antenna and the proposed antenna. The measured data show our proposed antenna is able to maintain the optimal communication link and avoid the polarization mismatching thanks to its inherited reconfigurability.