Provided is a planar horn array antenna includes: a waveguide part; a horn part having one side connected to the waveguide part and the other side formed with an opening for guiding a radio wave incident or emitted thereto; and a radio wave guide part having a dividing member coupled with the opening and consisting of circular dividing holes arranged in a matrix of n×n.

A horn (12) for elementary antennas for telecommunications, in particular satellite telecommunications, characterized in that the horn (12) includes a first emitting-receiving portion (22) adapted to emit and receiving an electromagnetic wave at a first frequency and a second emitting-receiving portion (24) adapted to emit and receiving an electromagnetic wave at a second frequency, the second emitting-receiving portion (24) being distinct and separate from the first emitting-receiving portion (22) and the ratio between the second frequency and the first frequency being greater than 1.2, preferably greater than 1.5.

The compact excitation module comprises two radiofrequency RF exciters and a rotary joint coupled together along a common longitudinal axis, the rotary joint comprising two distinct parts, respectively fixed and rotating around the common longitudinal axis, the two radiofrequency exciters being mounted one on each side of the rotary joint, respectively on the fixed and rotating parts, and axially coupled together by the rotary joint. The compact excitation module further comprises a rotary actuator provided with an axial transverse opening, the rotary joint being housed in the axial transverse opening of the rotary actuator.

An antenna system for satellite applications is provide, the antenna system comprising an antenna array and a feed structure, and the antenna array is a passive antenna array configured to have a first state and a second state, the second state being a first deployed state. The feed structure is configured to provide a linearly polarized incident field for the antenna array in the first deployed state. The antenna array comprises a plurality of array elements, and the plurality of array elements forms a polarization conversion surface configured for converting the linearly polarized incident field to a reflected/transmitted circular polarized field. The antenna array is configured so that the radiation pattern of the reflected/transmitted circular polarized field corresponds to a predetermined radiation pattern and an array element geometry and an array element position of each of the plurality array elements are configured to provide the predetermined radiation pattern.

A control system is presented for controlling operation of a phased-array antenna comprising N antenna elements each comprising H and V polarization terminals. The control system includes: an analogue circular polarization system (ACTS) and a digital polarization control system (DPCS). The ACPS comprises an array of N analogue circular polarization circuits (ACPCs) associated with said N antenna elements, respectively, such that each ACPC is connectable to the V and H polarization terminals of the respective antenna element. The ACPS is configured and operable with N analog circular polarization signal components each being either left or right circular polarization signal. The DPCS comprises: an array of N convertors associated with said N ACPCs, respectively, for converting between the N analog circular polarization (ACP) signals and N respective digital circular polarization (DCP) signals, such that each antenna element is associated with a respective single one of said N convertors; an array of N digital polarization controlled beamformers (DPCBs) connectable to said N convertors; and a plurality of digital signal splitters and/or combiners. Each DPCB comprises at least two beam forming channels associated with at least two, first and second, respective beams of different beam directions and/or different polarizations being operated by the antenna element, and is configured and operable to apply phase shifting to the respective DCP signal based on data indicative of a beaming direction (α) of a respective beam to be operated and the left or right polarization of circular polarization signal, and a relative phase (Φ) associated with the beaming direction (α) and a location of the respective antenna element in the array, to thereby form at least two phase shifted signals corresponding to said at least two, first and second, respective beams. Digital signal splitters and/or combiners operate to separately combine the phase shifted signals corresponding to respectively the at least first and second beams, wherein at least two convertors of said N convertors are connected to a respective one of the signal splitters and/or combiners, and wherein each digital splitter and/or combiner, connected to the at least two converters, converts between the DCP signals of opposite left and right circular polarizations of the at least two convertors and V and H linear polarization components and splits and/or combines the opposite left and right circular polarization signals of the at least two convertors.

An electromagnetic wave transmission structure adapted to cause convergence of an electromagnetic wave includes a substrate and a transmission unit provided on the substrate and including an annular metal plate. The annular metal plate has a weighted average inner radius and a weighted average outer radius each related to the wavelength of the electromagnetic wave, the distance between the electromagnetic wave transmission structure and a focal point defined as the point of convergence of the electromagnetic wave, and the distance between the source of the electromagnetic wave and the focal point. The plural inner and outer radii of the annular metal plate have the same trend of variation. Each inner or outer radius corresponds to a weight related to the reference included angle formed between the inner or outer radius and a reference axis.

An electromagnetic wave transmission structure adapted to cause convergence of an electromagnetic wave includes a substrate and a transmission unit provided on the substrate and including an annular metal plate. The annular metal plate has a weighted average inner radius and a weighted average outer radius each related to the wavelength of the electromagnetic wave, the distance between the electromagnetic wave transmission structure and a focal point defined as the point of convergence of the electromagnetic wave, and the distance between the source of the electromagnetic wave and the focal point. The plural inner and outer radii of the annular metal plate have the same trend of variation. Each inner or outer radius corresponds to a weight related to the reference included angle formed between the inner or outer radius and a reference axis.

An antenna apparatus may be disclosed. The antenna apparatus may include a feed network including a plurality of first internal transmission lines arranged in a cross form and a plurality of second internal transmission lines arranged in a ring form around the plurality of first internal transmission lines; and a plurality of radiation elements positioned around the feed network and radiating signals fed by the feed network.

An antenna apparatus may be disclosed. The antenna apparatus may include a feed network including a plurality of first internal transmission lines arranged in a cross form and a plurality of second internal transmission lines arranged in a ring form around the plurality of first internal transmission lines; and a plurality of radiation elements positioned around the feed network and radiating signals fed by the feed network.

Trapped or confined individuals may be located and rescued by detecting their vital signs (e.g., chest movement or heart beat) using reflected, radio frequency signals over a range of multiple antenna polarities.