Communications device with conductive Sinusoidal element and related antennas and methods
A communications device may include an RF device, and a circular cylindrical antenna coupled to the RF device. The circular cylindrical antenna may include a conductive ground plane, a conductive feed associated with the conductive ground plane, and a conductive sinusoidal element coupled to the conductive feed and extending outwardly from the conductive ground plane along a circular cylinder.
1 . A communications device comprising:
a radio frequency (RF) device; and
a circular cylindrical antenna coupled to the RF device and comprising
a conductive ground plane,
at least one conductive feed associated with the conductive ground plane, and
at least one conductive sinusoidal element coupled to the at least one conductive feed and extending outwardly from the conductive ground plane along a circular cylinder.
2 . The communications device of claim 1 wherein the at least one conductive sinusoidal element comprises a plurality of conductive sinusoidal elements; and wherein the at least one conductive feed comprises a plurality of conductive feeds with a respective conductive feed coupled to each conductive sinusoidal element.
3 . The communications device of claim 2 wherein the plurality of conductive sinusoidal elements comprises four conductive sinusoidal elements equally-sized and arranged about the circular cylinder.
4 . The communications device of claim 2 wherein the RF device is configured to operate with the circular cylindrical antenna in at least one of a right-handed circular polarization (RHCP), a left-handed circular polarization (LHCP), a first linear polarization, and a second linear polarization different from the first linear polarization.
5 . The communications device of claim 2 wherein adjacent ones of the plurality of conductive sinusoidal elements are nested together.
6 . The communications device of claim 1 wherein the circular cylindrical antenna comprises a circular cylindrical dielectric substrate; and wherein the at least one conductive sinusoidal element comprises at least one conductive trace on the circular cylinder dielectric substrate.
7 . The communications device of claim 1 wherein the conductive ground plane has a width greater than a diameter of the circular cylinder.
8 . The communications device of claim 1 wherein the at least one conductive feed comprises at least one coaxial cable feed coupling the RF device and the circular cylindrical antenna, the at least one coaxial cable feed comprising an inner conductor and an outer conductor surrounding the inner conductor; wherein the outer conductor is coupled to the conductive ground plane; and wherein the inner conductor extends through the conductive ground plane and is coupled to a proximal end of the at least one conductive sinusoidal element.
9 . The communications device of claim 1 wherein a proximal end of the at least one conductive sinusoidal element defines a gap with adjacent portions of the conductive ground plane.
10 . The communications device of claim 1 wherein the circular cylindrical antenna has an operating wavelength; wherein the circular cylinder has a diameter between 0.3 and 0.5 of the operating wavelength; wherein the circular cylinder has a height between 0.5 and 1 of the operating wavelength; and wherein the at least one conductive sinusoidal element defines a wave period between 0.1 and 0.3 of the operating wavelength.
11 . The communications device of claim 1 wherein the at least one conductive sinusoidal element has a shape based upon (d/4) sin (2πf)+0.8(d/4) sin (2πf); wherein f is an operating frequency of the circular cylindrical antenna; and wherein d is a diameter of the circular cylinder.
12 . A circular cylindrical antenna to be coupled to a radio frequency (RF) device, the circular cylindrical antenna comprising:
a conductive ground plane;
at least one conductive feed associated with the conductive ground plane; and
at least one conductive sinusoidal element coupled to the at least one conductive feed and extending outwardly from the conductive ground plane along a circular cylinder.
13 . The circular cylindrical antenna of claim 12 wherein the at least one conductive sinusoidal element comprises a plurality of conductive sinusoidal elements; and wherein the at least one conductive feed comprises a plurality of conductive feeds with a respective conductive feed coupled to each conductive sinusoidal element.
14 . The circular cylindrical antenna of claim 13 wherein the plurality of conductive sinusoidal elements comprises four conductive sinusoidal elements equally-sized and arranged about the circular cylinder.
15 . The circular cylindrical antenna of claim 13 wherein the at least one conductive sinusoidal element is configured to operate in at least one of a right-handed circular polarization (RHCP), a left-handed circular polarization (LHCP), a first linear polarization, and a second linear polarization different from the first linear polarization.
16 . The circular cylindrical antenna of claim 13 wherein adjacent ones of the plurality of conductive sinusoidal elements are nested together.
17 . The circular cylindrical antenna of claim 12 comprising a circular cylindrical dielectric substrate; and wherein the at least one conductive sinusoidal element comprises at least one conductive trace on the circular cylinder dielectric substrate.
18 . The circular cylindrical antenna of claim 12 wherein the at least one conductive feed comprises at least one coaxial cable feed coupled to the RF device, the at least one coaxial cable feed comprising an inner conductor and an outer conductor surrounding the inner conductor; wherein the outer conductor is coupled to the conductive ground plane; and wherein the inner conductor extends through the conductive ground plane and is coupled to a proximal end of the at least one conductive sinusoidal element.
19 . The circular cylindrical antenna of claim 12 wherein the at least one conductive sinusoidal element has an operating wavelength; wherein the circular cylinder has a diameter between 0.3 and 0.5 of the operating wavelength; wherein the circular cylinder has a height between 0.5 and 1 of the operating wavelength; and wherein the at least one conductive sinusoidal element defines a wave period between 0.1 and 0.3 of the operating wavelength.
20 . A method for making a circular cylindrical antenna to be coupled to a radio frequency (RF) device, the method comprising:
forming a conductive ground plane;
positioning at least one conductive feed associated with the conductive ground plane; and
forming at least one conductive sinusoidal element to be coupled to the at least one conductive feed and extending outwardly from the conductive ground plane along a circular cylinder.
21 . The method of claim 20 wherein the at least one conductive sinusoidal element comprises a plurality of conductive sinusoidal elements; and wherein the at least one conductive feed comprises a plurality of conductive feeds with a respective conductive feed coupled to each conductive sinusoidal element.
22 . The method of claim 21 wherein the plurality of conductive sinusoidal elements comprises four conductive sinusoidal elements equally-sized and arranged about the circular cylinder; and wherein adjacent ones of the plurality of conductive sinusoidal elements are nested together.
23 . The method of claim 21 wherein the circular cylindrical antenna is configured to operate in at least one of a right-handed circular polarization (RHCP), a left-handed circular polarization (LHCP), a first linear polarization, and a second linear polarization different from the first linear polarization.
24 . The communications device of claim 1 where the at least one conductive sinusoidal element has a variable rate of structural period.
25 . The circular cylindrical antenna of claim 12 where the at least one conductive sinusoidal element has a variable rate of structural amplitude.