Abstract:
Various antenna assemblies are disclosed. In one example, an antenna assembly includes a reflector including a first ground plane, a second ground plane below and spaced apart from the reflector, an antenna adjacent a surface of the reflector opposite the second ground plane, and a grounding post galvanically connecting the first ground plane and the second ground plane.
Abstract:
The present invention relates to an antenna arrangement connectable to a transceiver for transmitting and receiving RF signals in at least two separate frequency bands. The antenna arrangement has at least two sets of antenna elements arranged on a reflector, and the antenna elements are arranged in an interleaved configuration along a single column. The two separate frequency bands are substantially non-overlapping but relatively close to each other, and the distance between adjacent antenna elements in said column is substantially the same along the column.
Abstract:
A passive airborne mounted collision warning system suitable for light aircraft that enables an observer aircraft to determine the position of a nearby transponder-equipped target aircraft. The transponder-equipped target aircraft transmits replies responsive to interrogation signals from rotating secondary surveillance radars (SSR). In an embodiment of the invention, position of the target aircraft is determined based on the known position of the observer aircraft obtained e.g. via satellite navigation means such as GPS, the position of the SSR, and the bearing of the target aircraft measured by a direction finding antenna. The direction-finding antenna elements and the GPS receiver components are included in a device that is externally mounted on the observer aircraft. The data from the device is connected to a portable computer for processing and presentation to the pilot to alert him of the position of the target aircraft for avoiding collisions.
Abstract:
Method of manufacturing a transmission line including the steps : - forming an element with at least one longitudinal groove on a surface of said element, said longitudinal groove being defined by two opposite wall portions in the element and having a longitudinal opening adjacent to said surface, and - locating a conductor line in said at least one longitudinal groove. The method is distinguished by the steps: - forming the conductor line from a metal strip upon punching the same from a sheet of metal, - attaching the metal strip to at least one holding device, and - mounting said at least one holding device, with the attached metal strip, on said element, so as to locate said metal strip in said longitudinal groove at a distance from said opposite wall portions of said element. The invention also concerns a transmission line manufactured in accordance with said method.
Abstract:
The present invention is related to a dual band antenna 1 comprising a number of antenna elements for transmitting and/or receiving radio frequency radiation. The antenna elements are placed above each other, and a shielded feeding means 9 is provided through a first antenna element 2 to a second antenna element 3 for separately feeding the different antenna elements 2, 3.
Abstract:
There is disclosed an antenna element, including at least one antenna patch and a feeding arrangement which comprises: a ground plane including: a first aperture slot and a second aperture slot, where said aperture slots cross each other perpendicularly; a feeding plane including: a first antenna port for feeding microwave energy via a first feeding junction into a first pair of feed lines which extend in parallel along said first aperture slot, on each side thereof; a second antenna port for feeding microwave energy via a second feeding junction into a second pair of feed lines which extend in parallel along said second aperture slot, on each side thereof; and where said feed lines cross each other in at least one point, at a mutual distance. Said feeding arrangement is furthermore irregularly configured for compensating for an imbalance caused by said crossing of said feed lines.
Abstract:
An improved aperture-coupled planar antenna is disclosed, comprising a ground plane (5), an elongated feeding conductor (4) arranged in parallel with the ground plane (5), a conductive layer (2) provided with an elongated aperture (3) , a dielectric layer (1) arranged in parallel with the ground plane (5) and having fixed thereto, on a first side thereof, the elongated feeding conductor (4), and, on a second side thereof, the conductive layer (2), the elongated feeding conductor (4) intersecting the elongated aperture (3), and a dielectric carrier plate (13) having fixed thereon a radiating patch (14) arranged above and spaced from the conductive layer (2). The conductive layer (2) is attached to the ground plane (5) by a first spacer (6) extending from the ground plane (5) to the conductive layer (2) on the second side of the dielectric layer (1), the first spacer (6) functioning as a first mechanical support for the dielectric layer (1), an electrical connection between the conductive layer (2) and the ground plane (5), and a holder for a transmission line connector (8).
Abstract:
The present invention relates to an antenna arrangement comprising a first and third set of antenna elements, being arranged as a first and third column and aligned along a first and third symmetry axis, respectively, each column comprising elements being operative in a first frequency band (fl) and elements being operative in a second frequency band (f2) . The antenna arrangement further comprises a second set of antenna elements, being arranged as a second intermediate column along a second symmetry axis, said second symmetry axis being parallel to said first and third symmetry axes, and being operative in said second frequency band (f2) , wherein the ratio of said second centre frequency (f2) to said first centre frequency (fl) is in the range 1.5 to 3. The distance between said first and third symmetry axes is less than or equal to 0 .6 times the wavelength of said first centre frequency (fl) , and the distance between said second and said first and third symmetry axis, respectively, is less than or equal to 0.6 times the wavelength of said second centre frequency (f2).