Filtronic Wireless Ab

Powerwave Technologies Sweden Ab

Navaero Ab

Bjorn Lindmark

Jesper Uddin

Stefan Ridderheim

Hans Nystrom

An arrangement () comprising a first conductive antenna element (), comprising at least one first slot () arranged in the first conductive antenna element (), and a second conductive antenna element (), comprising at least one second slot () arranged in the second conductive antenna element (), is disclosed. At least one second slot () arranged in the second conductive antenna element () is coupled with at least one first slot () arranged in the first conductive antenna element () by means of at least one conductor ().

Arrangement comprising antenna elements

A broadband antenna of an antenna system comprises a conductive plate comprising four slots. The slots are arranged in a rotation symmetrical manner in the plate. Each slot extends from a circumference of the plate towards a center of the plate. Each slot has an associated feed point located at its associated slot. The feed points associated with a pair of oppositely arranged slots are arranged to be fed with radio frequency signals, such that that a main radiation propagation direction of the antenna is along the rotational symmetry axis of the plate. The antenna design enables the achievement of flexibility in terms of isolation between the two polarizations. The antenna design may further enable a reduced size and weight. The antenna design also enables an antenna unit and an antenna array.

Broadband antenna, multiband antenna unit and antenna array

An adjustable constant impedance phase shifter is provided. In the adjustable constant impedance phase shifter a conductive circuit path is arranged between a conductive sheet and a parallel plane that is parallel to the conductive sheet; an edge of a dielectric plate and an edge of a conductive plate are adjoined such that the dielectric plate and the conductive plate form a slide member; and the slide member is movably arranged along a slide path between the circuit element and the conductive sheet so that any point of the conducting circuit path is consistently enclosed between the slide member and the parallel plane, and so that the relative permittivity of a medium adjacent to a point on the conductive circuit path is simultaneously changed as the slide member is moved.

Adjustable constant impedance phase shifter

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 (f) and elements being operative in a second frequency band (f). 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 (f), wherein the ratio of said second center frequency (f) to said first center frequency (f) 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 center frequency (f), 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 center frequency (f).

Dual band antenna arrangement

A dual polarized antenna element having improved antenna isolation is disclosed by the present invention. The antenna element includes a first feeder for feeding the antenna element in a first polarization direction, and a second feeder for feeding the antenna element in a second polarization direction. According to the present invention, a compensation line is arranged between the first and the second feeders for compensating for an imbalance caused by an essentially capacitive coupling between the first and second feeders. The compensation line is connected to the first and second feeders in close proximity to a radiating part of said antenna element, and has a short electrical length &#x3b8; and a high impedance relative to an impedance of the first and second feeders, respectively, thereby giving the compensation line an essentially inductive character.

Antenna isolation

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.

Growing community of inventors

Taby, Sweden

Bjorn Lindmark