Circular Polarized Wide Beam Elliptical Microstrip Antenna for Energy Harvesting Application

A wide beam elliptical microstrip antenna circularly polarized is proposed for RF energy harvesting applications. Circular polarization is achieved by using single coaxial-fed elliptical microstrip antenna and exciting the degenerate even and odd modes corresponding to the fundamental TM 11 mode. Further, a cross-slot for perturbing the current distribution of the antenna to cause path difference corresponding to quarter wavelength. The proposed design has a 10 dB impedance bandwidth of equal to 0.1 GHz approximately and an axial ratio bandwidth of 0.02 GHz. A gain of around 3.8 dB and a wide beamwidth of 172 degrees. The overall antenna size is 70 mm x 70mm x 1.6 mm (0.58 λ 0 × 0.58 λ 0 × 0.013 λ 0 ). The antenna is suitable for use in RF energy harvesting applications from WiFi, Bluetooth and other devices operating in the 2.4 GHz ISM band.