Polarization Reconfigurable Eccentric Annular Ring Slot Antenna Design

A microstrip-fed reconfigurable eccentric annular ring slot (EARS) antenna with switchable polarization is proposed. To generate orthogonal circular polarization (CP) radiations, two identical perturbation slots (PSs) are loaded below the eccentric ring-shaped slot. By incorporating a PIN diode switch across each PS, the proposed antenna can switch between left-hand CP (LHCP), right-hand CP (RHCP), and linear polarization (LP). All three polarizations have shown good impedance bandwidth and broad CP bandwidth that can cover the WLAN 2.4 GHz operating band (2400-2480 MHz). Furthermore, desirable gains of 2.49-2.82 dBi and 2.94-3.24 dBic are also exhibited at LP and LHCP/RHCP, respectively.