5.8 GHz circular polarized rectifying antenna for microwave power transmission

This paper reports a new 5.8 GHz circular polarized (CP) high gain, high-efficiency rectifying antenna (rectenna). The CP rectenna can be rotated and still maintain a constant output voltage. A high-gain dual rhombic loop antenna and a reflecting plane are used to achieve a circular polarized antenna gain of 10.5 dB, a 2:1 VSWR bandwidth of 10 %, and average beamwidths of 43/spl deg/ and 59/spl deg/ In the E- and H-planes, respectively. The rectenna circuit has a coplanar stripline (CPS) band reject filter (BRF) which suppresses the re-radiated harmonics by 20 dB. A highly efficient Schottky diode is used for RF to DC conversion with an efficiency of approximately 80%.