Abstract: A low noise dual polarization electromagnetic power reception and conversion system is disclosed. It comprises a first plurality of conducting elements performing a bandpass function on incident waves, a second plurality of antenna units, located behind the first elements, performing a power reception and conversion function, and a third plurality of conducting elements located behind the antenna units, performing a bandstop function on incident signals. A layer of lossy material is optionally disposed behind the third elements to absorb any wave passing through them. This system can be used to achieve high efficiency power reception and conversion and also reduce levels of radiation of both harmonics of the powering frequency and intermodulation products formed by nonlinear mixing of signal wavefields from other users of the radio spectrum with the powering signal wavefield.

Abstract: A microwave-powered aircraft has lifting surfaces for exerting lifting forces on the aircraft in response to the propulsion of the aircraft and a rectenna array for receiving and rectifying microwave energy transmitted to the aircraft from a location remote from the aircraft. An electric motor for driving a propeller is energized by microwave energy received by the rectenna array, which is provided in a body at the underside of the aircraft. The body has its major dimensions extending horizontally and is relatively shallow with a periphery which is vertically curved so as to reduce turbulence in the airstream over the body during flight. The body is separate from the lifting surfaces and shaped to at least substantially avoid the generation of lifting forces by the body.

Abstract: An antenna array for receiving dual polarized electromagnetic waves, comprised of a first thin-film printed circuit rectenna having a plurality of linear half-wavelength dipole antennae oriented in a first direction for receiving a first component of the dual polarized waves, and a second thin-film printed circuit rectenna parallel to the first rectenna, having a plurality of linear half-wavelength dipole antennae oriented in a second direction for receiving the second orthogonal component of the electromagnetic waves. A reflector screen is disposed parallel and behind the second rectenna, for reflecting incident electromagnetic waves transmitted through the first and second rectennae back to the first and second rectennae for reception thereby.