A High-Gain Polarization Reconfigurable Printed Monopole Antenna for RF Energy Harvesting Application

In this paper, a high-gain and wideband polarization reconfigurable (CP) printed monopole antenna is reported. The proposed antenna consists of the linearly polarized (LP) Y-shaped monopole radiator with a conventional partial ground plane. To attain CP from LP, the partial ground plane is extended out, and shorted with one of the twin parasitic conducting strip [PCS(L)] by using a BAR 50-02V PIN Diode. Then, a circular-shaped PEC reflector of $0.026\lambda_{0}$ (thickness) is placed just below the monopole at a height of $0.33\lambda_{0}$ , to achieve wideband impedance bandwidth (IBW), 3-dB axial bandwidth (ARBW) with a high antenna gain, and strong boresight radiation pattern at 5 GHz bands required for RF energy harvesting application. An AMC wall is added in one side of the existing antenna geometry, to achieve higher gain with a variation of +1.5 dBic in the CP bands, over the case of a circular-shaped PEC reflector. So, the proposed antenna designed on a FR-4 substrate offers with impedance bandwidth (IBW) of 3.35 GHz (3.55 GHz-6.9 GHz), 3-dB axial bandwidth (ARBW) of 420 MHz (4.23-4.65 GHz), CP antenna gain > 9.25 dBic, peak antenna gain > 10.2 dBi with the antenna efficiency > 70%.