Omnidirectional cylindrical antenna
First Claim
1. An antenna array with a circular symmetry, said antenna comprising a cylindrical surface having a circumference;
- an array of elementary radiating sources in three layer printed circuits, each elementary radiating source being applied on said cylindrical surface;
a plurality of said elementary radiating sources being arranged in successive circular rows which are longitudinally distributed across said cylindrical surface;
said elementary radiating source centers in each circular row being angularly separated by a constant angular step, the sizes, angular width and longitudinal length of each elementary radiating source being substantially smaller than the circumference of the cylindrical surface;
each elementary radiating source having, when still planar and before being applied onto said cylindrical surface, a linearly polarized directive diagram;
adjacent elementary radiating source centers being separated by a distance in the order of 0.9 λ
o, where λ
o is the free space wavelength of a carrier frequency transmitted by the antenna, all said elementary radiating sources being fed in phase by signals having the same amplitude through a three conductor layer feed triplate line.
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Accused Products
Abstract
An antenna array with circular symmetry made up of an array of cylindrica shaped printed circuit elementary antennas. It is made up of small radiating sources which are placed in superposed circles on a cylindrical surface. The sources are distributed at constant angular intervals on the circles. They have little coupling between themselves. On each circle of sources, they are energized in phase and with the same amplitude. An angular phase shift can be provided between the group of sources on a circle and those of another circle. The antenna can be energized by a three-layer printed circuit line. It can be made up by an array of doublets folded into sheets. Inside the cylinder the transmitter is installed to which is applied a signal to be transmitted and which supplies the modulated carrier to the array of radiating sources.
49 Citations
7 Claims
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1. An antenna array with a circular symmetry, said antenna comprising a cylindrical surface having a circumference;
- an array of elementary radiating sources in three layer printed circuits, each elementary radiating source being applied on said cylindrical surface;
a plurality of said elementary radiating sources being arranged in successive circular rows which are longitudinally distributed across said cylindrical surface;
said elementary radiating source centers in each circular row being angularly separated by a constant angular step, the sizes, angular width and longitudinal length of each elementary radiating source being substantially smaller than the circumference of the cylindrical surface;
each elementary radiating source having, when still planar and before being applied onto said cylindrical surface, a linearly polarized directive diagram;
adjacent elementary radiating source centers being separated by a distance in the order of 0.9 λ
o, where λ
o is the free space wavelength of a carrier frequency transmitted by the antenna, all said elementary radiating sources being fed in phase by signals having the same amplitude through a three conductor layer feed triplate line. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- an array of elementary radiating sources in three layer printed circuits, each elementary radiating source being applied on said cylindrical surface;
Specification