Alford loop antennas with parasitic elements
View Patent ↗According to one embodiment of the invention, a network device comprises a plurality of antennas comprising a first antenna, wherein the first antenna comprises: a first set of one or more elements that form an Alford loop and that is configured for electrical excitation via a current transmitted over a conductive medium from a signal source and a second set of one or more elements that is configured for electromagnetic induction without contact with the conductive medium from the signal source.
1. A device comprising:
a plurality of antennas comprising an antenna array;
a first antenna among the plurality of antennas, wherein the first antenna includes:
a first set of elements that form an Alford loop, wherein:
the first set of elements are configured for electrical excitation via a current transmitted over a conductive medium from a signal source; and
the first set of elements are located in a center of a surface of a medium; and
a second set of elements configured for electromagnetic induction without contact with the conductive medium from the signal source, wherein the second set of elements are located in a periphery of the surface of the medium.
2. The device of claim 1 , wherein the second set of elements are parasitically coupled elements.
3. The device of claim 1 , wherein the second set of elements are configured for electromagnetic induction due to a change in charge and/or an electrical current on the Alford loop.
4. The device of claim 1 , wherein the device further comprises a ground plane, and wherein the first set of elements are less than 12 millimeters from the ground plane.
5. The device of claim 4 , wherein the second set of elements are less than 12 millimeters from the ground plane.
6. The device of claim 1 , wherein the device further comprises a ground plane, and wherein the second set of elements are less than 12 millimeters from the ground plane.
7. The device of claim 1 , wherein the second set of elements alters the pattern of the electric field produced by the Alford loop.
8. The device of claim 7 , wherein the second set of elements pull the electric field away from a portion of the ground plane directly below the first set of elements.
9. The device of claim 7 , wherein the second set of elements enlarges the effective aperture of the first antenna.
10. The device of claim 1 , wherein the device is an access point.
11. The device of claim 4 , wherein the device includes a second antenna among the plurality of antennas, and wherein:
the second antenna is different from the first antenna; and
the second antenna is disposed distal to a center of the ground plane, relative to the first antenna.