VHF Omni-range navigation system antenna
First Claim
1. A VOR antenna comprising a cylinder having four orthogonally disposed slots formed within the peripheral wall thereof, the slots extending in the direction of the longitudinal axis of the cylinder and being spaced-apart around the periphery of the cylinder, each slot being backed by a separate cavity which has a depth extending into the cylinder from the slot, the depth of each cavity being effectively greater than the radial dimension of the cylinder, and the cavities being configured to locate wholly within the cylinder.
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Accused Products
Abstract
An antenna which is suitable for use in a very high frequency omni-directional range (VOR) navigation system for aircraft. The antenna is driven to radiate reference and variable phase signals which provide flight bearing information to an aircraft which enters the radiated field.
The antenna comprises a cylindrical radiator which is formed with four orthogonally disposed longitudinally extending slots, and each slot is backed by a separate cavity which extends into the cylinder. Each cavity has an effective depth which is greater than the radial or, more usually, the diametral dimension of the cylinder, and all four cavities are configured so as to locate wholly within the cylinder.
26 Citations
13 Claims
- 1. A VOR antenna comprising a cylinder having four orthogonally disposed slots formed within the peripheral wall thereof, the slots extending in the direction of the longitudinal axis of the cylinder and being spaced-apart around the periphery of the cylinder, each slot being backed by a separate cavity which has a depth extending into the cylinder from the slot, the depth of each cavity being effectively greater than the radial dimension of the cylinder, and the cavities being configured to locate wholly within the cylinder.
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12. A VOR system comprising means for generating a reference phase signal, means for generating a variable phase signal, a cylindrical antenna having four orthogonally disposed longitudinally extending slots formed within the peripheral wall thereof, means for feeding the reference phase signal to all four slots, and means for feeding sine and cosine components respectively of the variable phase signal to orthogonally disposed pairs of the slots;
- each slot being backed by a separate cavity which as a depth extending into the cylinder from the slot, the depth of each cavity being effectively greater than the diametral dimension of the cylinder, and the cavities being configured to locate wholly within the cylinder.
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13. An antenna comprising a cylinder having four orthogonally disposed slots formed within the peripheral wall thereof, the slots extending in the direction of the longitudinal axis of the cylinder and being spaced-apart around the periphery of the cylinder, each slot being backed by a separate cavity which extends into the cylinder from the slot for a depth which is effectively greater than the diametrical dimension of the cylinder, the cavities being configured to locate wholly within the cylinder, and at least one conductive vane element being located within each of the cavities, the vane elements extending in a longitudinal direction for a portion of the length of the associated cavities, being disposed in non-conductive relationship between the side walls of the respective cavities, and being positionable in a rotational sense to present a selectively variable area of conductive material to the passage of electromagnet fields within the cavities.
Specification