Rectenna

A rectenna (rectifying antenna) is a device that receives microwave energy and converts it directly into direct current (DC) electricity using a combination of a receiving dipole or microstrip antenna and a rectifying diode circuit. Rectennas are the primary receiving technology for microwave-based wireless power transmission systems and would form the terrestrial receiving infrastructure for an SBSP system. The efficiency of individual rectenna elements can exceed 80% under optimal conditions. However, the overall system efficiency — including beam formation, atmospheric propagation, and conversion losses — is considerably lower. A full SBSP receiving station would consist of a large array of rectenna elements covering a substantial land or water area, connected to power conditioning equipment for grid injection. The rectenna concept was demonstrated by William Brown at Raytheon in 1964.