Contrawound toroidal helical antenna
First Claim
1. An electromagnetic device comprising:
- (a) a continuous first conductor comprising a first length portion and a second length portion, said first and second length portions of said continuous first conductor each of substantially the same length and joined to one another at first and second nodes, said first and second length portions each having a first end and a second end, said first end of said first length portion connected to said second end of said second length portion, said second end of said first length portion connected to said first end of said second length portion, said first end of said first length portion of said continuous first conductor overlaps said first end of said second length portion of said continuous first conductor, and said second end of said first length portion of said continuous first conductor overlaps with said second end of said second length portion of said continuous first conductor, the midpoints of said first and second length portions of said continuous first conductor are respective third and fourth nodes;
(b) a generalized toroid having a major axis and a minor axis, said continuous first conductor extending in a generalized helical pattern as a single closed circuit around and over the surface of said generalized toroid, said generalized helical pattern of said first length portion of said continuous first conductor having a first helical pitch sense, said generalized helical pattern of said second length portion of said continuous first conductor having a second helical pitch sense, said first helical pitch sense being opposite to said second helical pitch sense, said first and second length portions of said continuous first conductor insulated from one another and overlapping one another so as to collectively constitute a generalized contrawound toroidal helix, whereby said first and second nodes are in proximate location to one another and collectively constitute a first port on said generalized contrawound toroidal helix, and said third and fourth nodes are in proximate location to one another and collectively constitute a second port on said generalized contrawound toroidal helix;
(c) a signal feed located on said generalized contrawound toroidal helix;
(d) a signal coupler having a first port and a second port, said signal feed in electrical communication with said second port of said signal coupler, said second port of said signal coupler in electrical communication with said first port of said signal coupler;
(e) first and second signal terminals connected respectively to first and second terminals of said first port of said signal coupler.
4 Assignments
0 Petitions
Accused Products
Abstract
An electrically small antenna is constructed from a generalized contrawound toroidal helix made from a single continuous conductor divided into two length portions each of which are substantially the same length and which have a generalized helical pattern. The helical pitch senses the two length portions are opposite to one another. The two length portions are insulated from one another and overlap one another on the surface of a generalized toroid. A signal is fed to the antenna at a port defined by the node locations where the respective length portions join one another, or at a diametrically opposite point. At the fundamental mode of operation, the antenna is a half guided wavelength in circumference. The size of the antenna is further reduced because of the slow-wave properties of the underlying generalized contrawound toroidal helix. The antenna is omnidirectional with vertical polarization with a radiation pattern similar to an electric dipole, but in a physical package that is substantially smaller. A compact, broadband embodiment of the antenna is disclosed, as are other applications including a coaxial cavity resonator using the antenna as a feed element.
98 Citations
46 Claims
-
1. An electromagnetic device comprising:
-
(a) a continuous first conductor comprising a first length portion and a second length portion, said first and second length portions of said continuous first conductor each of substantially the same length and joined to one another at first and second nodes, said first and second length portions each having a first end and a second end, said first end of said first length portion connected to said second end of said second length portion, said second end of said first length portion connected to said first end of said second length portion, said first end of said first length portion of said continuous first conductor overlaps said first end of said second length portion of said continuous first conductor, and said second end of said first length portion of said continuous first conductor overlaps with said second end of said second length portion of said continuous first conductor, the midpoints of said first and second length portions of said continuous first conductor are respective third and fourth nodes; (b) a generalized toroid having a major axis and a minor axis, said continuous first conductor extending in a generalized helical pattern as a single closed circuit around and over the surface of said generalized toroid, said generalized helical pattern of said first length portion of said continuous first conductor having a first helical pitch sense, said generalized helical pattern of said second length portion of said continuous first conductor having a second helical pitch sense, said first helical pitch sense being opposite to said second helical pitch sense, said first and second length portions of said continuous first conductor insulated from one another and overlapping one another so as to collectively constitute a generalized contrawound toroidal helix, whereby said first and second nodes are in proximate location to one another and collectively constitute a first port on said generalized contrawound toroidal helix, and said third and fourth nodes are in proximate location to one another and collectively constitute a second port on said generalized contrawound toroidal helix; (c) a signal feed located on said generalized contrawound toroidal helix; (d) a signal coupler having a first port and a second port, said signal feed in electrical communication with said second port of said signal coupler, said second port of said signal coupler in electrical communication with said first port of said signal coupler; (e) first and second signal terminals connected respectively to first and second terminals of said first port of said signal coupler. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
-
-
32. A method of transmitting an electromagnetic signal, comprising the steps:
-
(a) applying a signal through first and second signal terminals such that the currents in said first and second signal terminals flows in opposite directions; and (b) conducting said currents from said first and second signal terminals to first and second nodes on a continuous first conductor, said nodes dividing said continuous first conductor into first and second length portions each of substantially the same length, said first and second length portions each having a first end and a second end, said first end of said first length portion connected to said second end of said second length portion, said second end of said first length portion connected to said first end of said second length portion, said first end of said first length portion of said continuous first conductor overlaps said first end of said second length portion of said continuous first conductor, and said second end of said first length portion of said continuous first conductor overlaps said second end of said second length portion of said continuous first conductor, said continuous first conductor extending in a generalized helical pattern as a single closed circuit around and over the surface of a generalized toroid, said generalized helical pattern of said first length portion having a first helical pitch sense, said generalized helical pattern of said second length portion having a second helical pitch sense, said first helical pitch sense being opposite to said second helical pitch sense, said first and second length portions of said continuous first conductor insulated from one another and overlapping one another so as to collectively constitute a generalized contrawound toroidal helix. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
-
Specification