The present disclosure relates to a compact antenna test range (CATR) system. The CATR system comprises a measurement chamber, at least one feed antenna which is configured to transmit a radio frequency, RF, signal, at least one reflector which is arranged to reflect the RF signal towards a measurement area in the measurement chamber, and at least two preferably metallic calibration surfaces which can be arranged at two or more positions in the measurement area, wherein the calibration surfaces are configured to reflect a respective reflection of the RF signal back to the at least one reflector which is, in turn, configured to reflect the reflections of the RF signal back to the at least one feed antenna. The CATR system further comprises a measurement unit which is configured to receive the respective reflections of the RF signal and to determine and/or visualize a time difference between the reception of the respective reflections of the RF signal.

An imaging array fed reflector for a spacecraft is included in a spacecraft payload subsystem. The payload subsystem includes a multi-beam antenna including a reflector, a plurality of amplifiers, and a plurality of radiating feed elements, the feed elements configured as a phased array, illuminating the reflector, operable at a frequency having a characteristic wavelength (λ), and configured to produce, in a far field at the reflector, a set of contiguous abutting beams. The amplifiers are disposed proximate to the plurality of radiating feed elements. Each radiating feed element has a respective coupling with at least one respective amplifier of the plurality of amplifiers. Each radiating feed element, together with the at least one respective amplifier, is disposed in a closely packed triangular lattice such that separation between adjacent radiating feed elements is not greater than 1.5λ.

An imaging array fed reflector for a spacecraft is included in a spacecraft payload subsystem. The payload subsystem includes a multi-beam antenna including a reflector, a plurality of amplifiers, and a plurality of radiating feed elements, the feed elements configured as a phased array, illuminating the reflector, operable at a frequency having a characteristic wavelength (λ), and configured to produce, in a far field at the reflector, a set of contiguous abutting beams. The amplifiers are disposed proximate to the plurality of radiating feed elements. Each radiating feed element has a respective coupling with at least one respective amplifier of the plurality of amplifiers. Each radiating feed element, together with the at least one respective amplifier, is disposed in a closely packed triangular lattice such that separation between adjacent radiating feed elements is not greater than 1.5λ.

An antenna device comprising: one or more substrates; a first radiating element disposed on a first region of a surface of the one or more substrates that face a cover covering the antenna device: a second radiating element disposed on a second region of the surface of the one or more substrates that face the cover; a first reflecting plate that reflects an electromagnetic wave from the first radiating element; and a second reflecting plate that reflects an electromagnetic wave from the second radiating element, wherein the first reflecting plate and the second reflecting plate take different positions in a direction perpendicular to the surface of the one or more substrates that face the cover, and the first region and the second region are regions that do not overlap each other on the surface of the one or more substrates that face the cover.

An antenna device comprising: one or more substrates; a first radiating element disposed on a first region of a surface of the one or more substrates that face a cover covering the antenna device: a second radiating element disposed on a second region of the surface of the one or more substrates that face the cover; a first reflecting plate that reflects an electromagnetic wave from the first radiating element; and a second reflecting plate that reflects an electromagnetic wave from the second radiating element, wherein the first reflecting plate and the second reflecting plate take different positions in a direction perpendicular to the surface of the one or more substrates that face the cover, and the first region and the second region are regions that do not overlap each other on the surface of the one or more substrates that face the cover.

A system includes a first antenna and a second antenna. The first antenna includes an antenna section. The antenna section includes a first antenna segment, a second antenna segment adjacent to the first antenna segment, and a notch circuit disposed within a notch between the first antenna segment and the second antenna segment. The notch circuit prevents a first frequency of a signal from passing from the first antenna segment to the second antenna segment while allowing a second frequency from the signal to pass from the first antenna segment to the second antenna segment. The second antenna is disposed proximate to the first antenna. The first antenna occupies a second near field region of the second antenna and the second antenna occupies a first near field region of the first antenna.

A system includes a first antenna and a second antenna. The first antenna includes an antenna section. The antenna section includes a first antenna segment, a second antenna segment adjacent to the first antenna segment, and a notch circuit disposed within a notch between the first antenna segment and the second antenna segment. The notch circuit prevents a first frequency of a signal from passing from the first antenna segment to the second antenna segment while allowing a second frequency from the signal to pass from the first antenna segment to the second antenna segment. The second antenna is disposed proximate to the first antenna. The first antenna occupies a second near field region of the second antenna and the second antenna occupies a first near field region of the first antenna.

An electromagnetic wave reflector includes a panel having a reflective surface that reflects a radio wave of a frequency band selected from 1 GHz to 170 GHz, and a support body that supports the panel. The support body has a connector part electrically connected to the reflective surface, the connector part being configured to propagate a reference potential of a reflection having occurred at the reflective surface.

An electromagnetic wave reflector includes a panel having a reflective surface that reflects a radio wave of a frequency band selected from 1 GHz to 170 GHz, and a support body that supports the panel. The support body has a connector part electrically connected to the reflective surface, the connector part being configured to propagate a reference potential of a reflection having occurred at the reflective surface.

An electromagnetic-radiation-reflecting structure that is attached at a location on a user's body. The electromagnetic-radiation-reflecting structure generating, as the user proceeds in usual fashion, a micro-Doppler effect as a result of its attachment at the location on the body so that a radar cross section of the user is increased, a material of the electromagnetic-radiation-reflecting structure having a conductivity greater than 100 S/m or a conductivity less than 100 S/m, a relative permeability between 100 and 10.sup.5, and a relative permittivity between 1 and 14; or has a conductivity less than 100 S/m, a relative permeability between 1 and 100, and a relative permittivity between 7 and 14; and a surface area of the electromagnetic-radiation-reflecting structure (120) is greater than 1000 mm.sup.2.