Continuous band antenna (CBA) with switchable quadrant beams and selectable polarization
An antenna formed from one or more structures with sets of radiating elements oriented in four different, preferably orthogonal, directions. The radiating elements are further provided as multiple horizontal and vertical radiating section. The structure may be a six sided cube-like structure or a cylinder. A combining circuit provides omnidirectional, directional, and scanning/direction finding modes across a broad operating frequency range with multiple polarizations. The arrangement lends itself to implementation as a whip form factor well suited for vehicular applications.
1. An antenna comprising:
a structure having sets of antenna elements generally facing in four different orthogonal directions, with each set of antenna elements including four radiating segments, at least two of the radiating segments providing a respective horizontal and vertical polarization;
a selector module situated within the structure, the selector module providing at least a horizontal and vertical polarization transmission line extending from corresponding horizontal and vertical polarization segments of the four sets of radiating elements; and
a combining circuit connected to the transmission lines, to selectively enable a directional mode, omnidirectional mode, and polarization modes.
2. The antenna of claim 1 wherein the radiating segments are triangular in shape.
3. The antenna of claim 2 wherein the radiating segments of each set include two horizontally polarized triangular segments and two vertically polarized triangular segments.
4. The antenna of claim 1 wherein the structure is a six-sided structure.
5. The antenna of claim 1 wherein the structure is a cylinder.
6. The antenna of claim 1 wherein the combining circuit further provides
vertical, horizontal, right-hand circular and left-hand circular polarization modes.
7. The antenna of claim 1 wherein the directional mode is selected by feeding a set of elements facing a desired direction of radiation and shortening transmission lines from the other three directions.
8. The antenna of claim 1 wherein a circular polarization mode is selected by feeding the horizontal and vertical elements of a set of elements with a quadrature hybrid combiner.
9. The antenna of claim 1 wherein the omnidirectional mode is provided by feeding all of the segments in phase with one another.
10. The antenna of claim 1 wherein the combining circuit is disposed in a middle portion of the structure.
11. The antenna of claim 10 wherein the combining circuit is disposed equidistant from the four sets of elements.
12. The antenna of claim 1 wherein the combining circuit is disposed in a middle portion of the structure.
13. An antenna comprising:
a first structure having sets of antenna elements generally facing in four different orthogonal directions, with each set of antenna elements including four radiating segments, at least two of the radiating segments providing a respective horizontal and vertical polarization;
a second structure having sets of antenna elements generally facing in four different orthogonal directions, with each set of antenna elements including four radiating segments, at least two of the radiating segments providing a respective horizontal and vertical polarization;
to a dipole antenna element; and
the first and second structures and the dipole antenna element each coaxially disposed with respect to one another along a center axis.
14. The antenna of claim 13 additionally comprising:
a selector module situated within each of the first and second structures, the selector modules providing at least a horizontal and vertical polarization transmission line extending from corresponding horizontal and vertical polarization segments of the four sets of radiating elements of each structure.
15. An antenna comprising:
a structure having sets of antenna elements generally facing in four different orthogonal directions, with each set of antenna elements including four radiating segments, at least two of the radiating segments providing a respective horizontal and vertical polarization;
a selector module situated within the structure, the selector module providing at least a horizontal and vertical polarization transmission line extending from corresponding horizontal and vertical polarization segments of the four sets of radiating elements; and
a combining circuit connected to the transmission lines.
16. The antenna of claim 15 wherein the combining circuit is disposed equidistant from the four sets of elements.