Highly Efficient 900 MHz Minkowski Rectenna for RF Energy Harvesting Applications

The compact rectifying antenna (rectenna) proposed in this presentation consists in a 1st iteration fractal Minkowski loop antenna associated with rectifying circuit. The loop antenna has been simulated and optimized. It occupies the perimeter of 0.74 wavelength at the operating frequency of 900 MHz. The reflection coefficient is about -26dB at 900 MHz. The antenna had a realized gain of2 dBi and a transfer function of 0.08 m. It also presents an efficiency of 91%. The rectifying circuits are composed of a low threshold single series diode, one capacitor and a single load. This single load is a 10 $\mathrm{k}\Omega$ resistor, which represents the input impedance of the DC-DC boost charger. The whole rectenna has been simulated and it presents 55% as the RF-DC conversion efficiency for a power density of 1 uW/cm2.