A measurement system is provided. The measurement system comprises a device under test, at least two measurement antennas, and a reflector. In this context, the reflector comprises at least two separate curved surfaces in the same physical entity in order to generate separate plane waves corresponding to the at least two measurement antennas. The reflector is configured in such a manner that the separate plane waves converge in a quiet-zone comprising the device under test.

An auxiliary antenna is provided that enables communication between a small antenna of an RFID tag and an antenna of a reader device without using a small antenna as the antenna of the reader device. The auxiliary antenna is an auxiliary antenna configured to expand a communication range of an antenna of an RFID tag to enable communication between the small antenna included in the RFID tag and an antenna included in a reader device. The auxiliary antenna includes a resonance loop group in which a plurality of resonance loops having a resonance frequency corresponding to a communication frequency is arranged to be coupled through a magnetic field. Moreover, the resonance loop group has an antenna area larger than the antenna area of the antenna of the RFID tag and equivalent to or larger than the antenna area of the antenna of the reader device.

A system, in a programmable active reflector (AR) device associated with a first radio frequency (RF) device and a second RF device, receives a request and associated metadata from the second RF device via a first antenna array. Based on the received request and associated metadata, one or more antenna control signals are received from the first RF device. The programmable AR device is dynamically selected and controlled by the first RF device based on a set of criteria. A controlled plurality of RF signals is transmitted, via a second antenna array, to the second RF device within a transmission range of the programmable AR device based on the associated metadata. The controlled plurality of RF signals are cancelled at the second RF device based on the associated metadata.

Methods, systems, and devices are described that include one or more septum features to improve performance of a waveguide device. In particular, the septum features may be utilized within a polarizer section of a polarizer device such as a septum polarizers. The septum feature(s) may be a ridge. When a plurality of septum features are employed, the location, size, shape and spacing may vary according to a particular design.

An antenna apparatus includes: an antenna array that: i) includes a plurality of antennas arranged next to each other in a predetermined direction, ii) is supplied with power from a power source, and iii) transmits radio waves; and a plurality of dummy antennas that: i) are provided on opposite sides of the antenna array in the predetermined direction, ii) are supplied with power from an electric field leaked from the antennas of the antenna array, and iii) transmit radio waves. Thus, it is possible to prevent an accuracy of detecting a target from deteriorating.

An antenna system includes a circularly-polarized antenna element with a Down/Up ratio in a proximity of a local horizon of no better than 12 dB. An antenna radome encloses the antenna element, the radome providing a drop of antenna pattern near a local horizon and having an upper transparent area and a lower semi-transparent area. The semi-transparent area is has a generally hemispherical shape. The semi-transparent area includes a circular metallized portion with vertical and horizontal slots, the metallized portion extending part of the way downward from an equator of the generally hemispherical shape. The metallized portion includes passive discrete electrical elements connected across at least some of the slots. The metallized portion can include multiple areas having different degrees of transparence. Each such area has a specified impedance. The discrete elements are capacitors, inductors and/or resistors. The metallized portion can have a plurality of circular rows separated by the horizontal slots.

An antenna structure according to an embodiment of the present disclosure includes a dielectric layer and a plurality of antenna units arranged on a top surface of the dielectric layer. Each of the plurality of antenna units includes a radiator, a first transmission line and a second transmission line extending in different directions to be connected to the radiator, an upper parasitic element adjacent to an upper portion of the radiator, and a lower parasitic element adjacent to a lower portion of the radiator.

An antenna structure according to an embodiment of the present disclosure includes a dielectric layer and a plurality of antenna units arranged on a top surface of the dielectric layer. Each of the plurality of antenna units includes a radiator, a first transmission line and a second transmission line extending in different directions to be connected to the radiator, an upper parasitic element adjacent to an upper portion of the radiator, and a lower parasitic element adjacent to a lower portion of the radiator.

An antenna array assembly comprises a ground plate, an array of radiator elements disposed in a spaced relationship with a first face of the ground plate between first and second substantially parallel conductive walls projecting from the first face of the ground plate, and a first and second conductive plate. Each of the first and second conductive plates is electrically isolated from the ground plate, and each is disposed in an upstanding relationship to the first face of the ground plate in a substantially parallel relationship with the first and second conductive walls. This provides reduced radiation in at least one direction in the hemisphere on the opposite side of the ground plate to the first face.

A radome for a concave-reflector antenna is fastened directly onto the reflector's edge. The inner surface of the radome comprises at least one absorbent part partially covering its surface area and disposed along its peripheral edge. The surface area of the radome covered by the absorbent part(s) is less than 15% of the total surface area. The radome may comprise two absorbent parts in diametrically opposite positions. Each absorbent part may have a substantially triangular shape, the base of the absorbent part being rounded along the radome's edge, and a portion of its surface area having been removed laterally from each side of the triangle in a circular arc cut-out.