An antenna includes a ground layer, two polarization signal feeding terminals disposed on the ground layer, two polarization structures, four coupling metals and four radiating metals. The first polarization structure includes a first extending portion electrically connected to the first polarization signal feeding terminal and extends from a first channel to a second channel in a first direction over the ground layer. The second polarization structure includes a second extending portion electrically connected to the second polarization signal feeding terminal and extends from a third channel to a fourth channel in second direction over the ground layer, wherein the first extending portion crosses the second extending portion in a non-contact manner to define four regions. The four coupling metals are disposed on the first through the fourth regions, respectively. The four radiating metals are disposed on the first through the fourth channels, respectively.

A compact munition antenna system that includes a curvilinear transmit antenna on a top and bottom of a ring-shaped substrate, and a curvilinear receive antenna on the top and bottom of the substrate. The transmit antenna and receive antenna are positioned opposite one another on the substrate, and are separated by a pair of isolation barriers to reduce coupling of the two antennas. The munition antenna system may be mounted on a metal cylindrical portion of a guidance system in a nose section of the munition, using a vertical convex surface of the cylindrical portion and a horizontal surface of the munition as a reflector for improving antenna performance.

A twin beam base station antenna includes a first array that has a plurality of columns of first frequency band radiating elements, the first array configured to form a first antenna beam that provides coverage throughout a first sub-sector of a three-sector base station. The radiating elements in a first of the columns in the first array have a first azimuth boresight pointing direction and the radiating elements in a second of the columns in the first array have a second azimuth boresight pointing direction that is offset from the first azimuth boresight pointing direction by at least 10°. The radiating elements in the second of the columns in the first array are electrically steered.

An antenna has a reflector and an active element. The reflector includes a multi-segment metal structure having a length within a first value range. The multi-segment metal structure includes a first metal structure connected to a second metal structure. A PIN diode is disposed on the first metal structure. The first metal structure is parallel to a polarization direction of the active element. The second metal structure is perpendicular to the first metal structure.

This antenna device is provided with: an antenna element disposed in a recessed portion of the exterior of a moving body; and a passive element which is disposed in a position higher than a flat surface in the recessed portion on which the antenna element is positioned.

An antenna device includes a substrate, a first antenna element extending in a direction perpendicular to a first surface of the substrate and functioning as a monopole antenna, a second antenna element provided adjacent to the first antenna element, extending in the direction perpendicular to the first surface of the substrate, and functioning as a monopole antenna, a ground layer provided in or on the substrate, a connection wire provided in or on the substrate and connecting the first antenna element and the second antenna element to each other, a power feeding line provided in or on the substrate and connected to the connection wire, and a first reflector provided in a direction in which the first antenna element and the second antenna element are adjacent to each other and facing the first antenna element and the second antenna element.

An antenna element for a multi-band antenna device includes a dielectric body provided with one or more metal layers. The dielectric body includes a base plate and one or more wall elements arranged on the base plate. One or more first radiating elements and one or more second radiating elements are arranged on the base plate, and are configured to radiate in a first and a second frequency band, respectively. A first feeding network is connected to the first radiating elements and a second feeding network is connected to the second radiating elements, for operating the first and second radiating elements as a first and second antenna array, respectively. The first feeding network is provided, at least partly, as a metal layer of the one or more metal layers on the one or more wall elements.

A multi-frequency array antenna, includes a reflective metal plate, a low-frequency radiation column element which is arranged on the reflective metal plate and operating in a first frequency band range, and a high-frequency radiation column element operating in a second frequency band range. The low-frequency radiation column element comprises several low-frequency radiation units arranged at an equal first distance in the axial direction of a first reference axis. The high-frequency radiation column element comprises several high-frequency radiation units arranged at an equal second distance in the axial direction of the first reference axis. The first distance is 2.5 times the second distance. At least one of the low-frequency radiation units is nested with one high-frequency radiation unit locationally corresponding thereto, and at least one of the low-frequency radiation units is axially located between two adjacent high-frequency radiation units close to the low-frequency radiation unit.

A first step sets a second inclination angle of a housing to an angle different from a reference housing angle by a limit angle; drives an actuator to set a first inclination angle to an angle different from a substrate inclination angle by the limit angle such that a beam axis is kept to be oriented to a specified direction; and measures, based on transmission and reception of a radar beam, first received power. A second step drives the actuator to set the first inclination angle to an angle located outside the adjustment range by a predetermined additional angle while the first inclination angle is maintained; and measures, based on transmission and reception of the radar beam, second received power. A third step determines whether a difference between the first received power and the second received power is greater than a predetermined determination threshold, and checks an operating state of the actuator based on a result of the determination.

A communication device includes an antenna system, a metal base, and a metal elevating pillar. The antenna system at least includes a dual-polarized antenna and a reflector. The reflector is configured to reflect radiation energy from the dual-polarized antenna. The metal elevating pillar is coupled between the antenna system and the metal base, and is configured to support the antenna system.