5.8 GHz circular polarized rectenna for microwave power transmission

This paper introduces a new circular polarized (CP) high-efficiency rectifying antenna (rectenna) array. The array elements are etched on Rogers Duroid 5870 substrate with /spl epsi//sub r/=2.33 and 10 mil thickness. The rectenna uses a dual rhombic loop antenna with a circular polarized gain of 11.7 dB and a beamwidth of 45/spl deg//55/spl deg/. The rectenna circuit has a coplanar stripline (CPS) low pass filter (LPF) which suppresses harmonics below 15 dB. The maximum RF to DC conversion efficiency of the rectenna's diode is 67%.