Characterization of a Schottky Diode Rectenna for Millimeter Wave Power Beaming Using High Power Radiation Sources

Two principal elements play a role in a wireless power beaming system: a high power radiation source as the transmitter and a rectifying antenna (rectenna) as an RF to DC converter at the receiving site. A millimeter wave power transmission is analyzed using transmission system and a W-band rectenna based on a low-barrier Schottky diode. A quasi-optical approach is presented here, using free-space Gaussian propagation and optical ABCD matrices for lenses. Experiments are made to estimate the optimal load resistance and power handling capability of a single rectifier. A low power W-band tunable solid-state source delivering 0.4 W CW power equipped by the focusing lenses is used to characterize the responsivity of the rectenna. A pulsed power gyrotron is used to identify the diode breakdown point. It was found that the RF-to-DC conversion efficiency corresponding to the optimal load of 200 Ω is about 20.5% while the maximum DC power converted by the diode with optimal load is about 15 mW before breakdown.