A Reconfigurable T-shaped Slot Antenna Using Characteristic Mode Analysis

This paper proposes a circular polarization (CP) reconfigurable T-shaped slot antenna. Characteristic mode analysis (CMA) is carried out to understand the physical mechanism of a stand-alone T-shaped conductor laminate, from which modal current distribution over the conducting plane suggests how the circular polarization can be fulfilled. Furthermore, by using a pair of PIN diodes, the antenna is capable of switching its polarization from right hand circular polarization (RHCP) to left hand circular polarization (LHCP) and vice versa. The antenna targets at the 2.4-GHz band. The simulated overlapped -10-dB reflection coefficient and 3-dB axial-ratio bandwidths is 4.5%.