Aerial inventory antenna
The present invention teaches a frequency-scalable high-gain dual-polarization radio beam application platform for private, public, government, or military radio applications such as RFID (radio frequency identification), aerial and robotic inventory scanning, radio communications, telemetry, telecommand, aeronautical radionavigation, radiolocation, earth exploration, space research for terrestrial, air-to-ground, space-to-earth, or space-to-space uses.
1. A dual polarization antenna comprising:
a hollow central core wherein the outer skin is electrically conductive;
a two-port radio module wherein the module is located within the hollow central core with a first and a second antenna feed point extending through the surface of the skin;
a toroidal reflector loop located below the hollow central core;
a first helical exciter element located above the reflector loop wherein the proximal end of the exciter curls inward to connect with the first antenna feed point;
a second helical exciter element located above the first helical exciter element wherein the proximal end of the exciter curls inward to connect with the second antenna feed point; and
a toroidal director loop located above the second helical exciter element.
2. The antenna of claim 1 further comprising a first non-conductive helical support member and a second non-conductive helical support member located above the first non-conductive helical support member.
3. The antenna of claim 2 , wherein the first exciter element is supported at two points by the first helical support member and the second exciter element is supported at two points by the second helical support member.
4. The antenna of claim 3 , wherein the first helical support member supports the distal end of the second exciter.
5. The antenna of claim 3 , wherein the second helical support member supports the distal end of the first exciter.
6. The antenna of claim 1 , wherein the reflector, exciters, and director elements are made of half hard brass wire.
7. The antenna of claim 1 , wherein the proximal ends of the exciters are fed by an impedance-matching network.
8. The antenna of claim 1 , wherein the exciters are mechanically supported at low voltage points.
9. The antenna of claim 1 , wherein the outer skin is thermally conductive.
10. The antenna of claim 1 , wherein the diameter of the reflector element is about 4.4 inches.
11. The antenna of claim 1 , wherein the diameter of the helical elements are about 4.0 inches with about 1.2 inches between the turns.
12. The antenna of claim 1 , wherein the diameter of the director element is about 3.7 inches.
13. The antenna of claim 1 , wherein the two-port radio module is an RFID interrogator.