Dynamically adjusting width of beam based on altitude
View Patent ↗An antenna includes a radiator and a reflector and has a radiation pattern that is based at least in part on a separation distance between the radiator and the reflector. The antenna includes a linkage configured to adjust the separation distance based at least in part on the altitude of the antenna. The resulting radiation pattern can be dynamically adjusted based on altitude of the antenna such that, while the antenna is aloft and the antenna is ground-facing, variations in geographic boundaries and intensity of the radiation received at ground level are at least partially compensated for by the dynamic adjustments to the radiation pattern.
1. An antenna configured to be mounted to an aerial vehicle, the antenna comprising:
a radiator configured to emit radiation according to a feed signal;
a reflector configured to direct radiation emitted from the radiator such that reflected radiation is characterized by an emission pattern determined at least in part by a separation distance between the radiator and the reflector, wherein the reflector is configured to be situated such that the emission pattern is directed in a ground-facing direction while the aerial vehicle is aloft; and
a linkage configured to adjust the separation distance between the radiator and the reflector according to an altitude of the aerial vehicle.
2. The antenna according to claim 1 , wherein the linkage includes a vessel arranged such that a change in volume of the vessel causes a corresponding change in the separation distance between the radiator and the reflector.
3. The antenna according to claim 2 , wherein the vessel is configured such that the volume of the vessel is based on ambient pressure, thereby causing the separation distance to be based at least in part on the ambient pressure.
4. The antenna according to claim 2 ,
wherein the vessel includes end caps connected between one or more sidewalls having a plurality of ribs to allow the vessel to change volume, in response to changes in ambient pressure, substantially by expanding or contracting a length of the one or more sidewalls, via the plurality of ribs, thereby changing a distance between the end caps, and
wherein the end caps are connected such that the separation distance between the radiator and the reflector corresponds to the distance between the end caps.
5. The antenna according to claim 4 ,
wherein the vessel includes a generally cylindrically-shaped aneroid with at least partially corrugated metallic sidewalls, and
wherein an internal chamber of the vessel is substantially evacuated.
6. The antenna according to claim 1 , further comprising a controller configured to: (i) determine the altitude of the aerial vehicle, and (ii) cause the linkage to adjust the separation distance between the radiator and the reflector based on the determined altitude.
7. The antenna according to claim 1 , wherein the linkage is further configured to dynamically adjust the separation distance between the radiator and the reflector by: (i) reducing the separation distance responsive to an increase in altitude of the antenna, and (ii) increasing the separation distance responsive to a decrease in altitude of the antenna.
8. The antenna according to claim 1 , wherein the separation distance is dynamically adjusted such that, in a geographical region receiving the emitted radiation at ground level, variations in intensity of the received radiation at ground level due to variations in altitude of the aerial vehicle are at least partially compensated for.
9. The antenna according to claim 1 , wherein the separation distance is dynamically adjusted such that, in a geographical region receiving the emitted radiation at ground level, variations in a boundary of the geographical region receiving the radiation due to variations in altitude of the aerial vehicle are at least partially compensated for.
10. The antenna according to claim 1 , wherein the antenna is further configured to receive radiation from a region defined by the emission pattern.
11. The antenna according to claim 1 , wherein the antenna is further configured to transmit signals to radio stations at ground level.
12. An aerial vehicle comprising:
an envelope;
a payload configured to be suspended from the envelope; and
an antenna mounted to the payload and situated so as to be ground-facing while the aerial vehicle is aloft, the antenna including: (i) a radiator configured to emit radiation according to feed signals; (ii) a reflector configured to direct the radiation emitted from the radiator according to a radiation pattern determined at least in part according to a separation distance between the radiator and the reflector; and (iii) a linkage configured to adjust the separation distance between the radiator and the reflector according to an altitude of the aerial vehicle.
13. The aerial vehicle according to claim 12 , wherein the linkage includes a vessel arranged such that a change in volume of the vessel causes a corresponding change in the separation distance between the radiator and the reflector.
14. The aerial vehicle according to claim 13 , wherein the vessel is configured such that the volume of the vessel is based on ambient pressure, thereby causing the separation distance to be based, at least in part, on the ambient pressure.
15. The aerial vehicle according to claim 13 ,
wherein the vessel includes end caps connected between one or more sidewalls having a plurality of ribs to allow the vessel to change volume, in response to changes in ambient pressure, substantially by expanding or contracting a length of the one or more sidewalls, via the plurality of ribs, thereby changing a distance between the end caps,
wherein the end caps and the one or more sidewalls enclose an inner chamber that is substantially evacuated, and
wherein the end caps are connected such that the separation distance between the radiator and the reflector corresponds to the distance between the end caps.
16. The aerial vehicle according to claim 12 , further comprising a controller configured to: (i) determine the altitude of the aerial vehicle, and (ii) cause the linkage to adjust the separation distance between the radiator and the reflector based on the determined altitude.
17. The aerial vehicle according to claim 12 , wherein the linkage is further configured to dynamically adjust the separation distance between the radiator and the reflector by: (i) reducing the separation distance responsive to an increase in altitude of the aerial vehicle, and (ii) increasing the separation distance responsive to a decrease in altitude of the aerial vehicle.
18. A method comprising:
emitting radiation from an antenna configured to be mounted to a payload of an associated aerial vehicle, wherein the antenna has an emission pattern determined at least in part by a separation distance between a radiator and a reflector of the antenna, and wherein the antenna is configured to be situated such that the emission pattern is directed in a ground-facing direction while the associated aerial vehicle is aloft and the antenna is mounted to the payload;
decreasing the separation distance between the radiator and the reflector responsive to a decrease in altitude of the associated aerial vehicle; and
increasing the separation distance between the radiator and the reflector responsive to an increase in altitude of the associated aerial vehicle.
19. The method according to claim 18 , further comprising:
determining the altitude of the associated aerial vehicle; and
causing the linkage to adjust the separation distance between the radiator and the reflector based on the determined altitude.
20. The method according to claim 18 ,
wherein the linkage includes a vessel arranged such that a change in volume of the vessel causes a corresponding change in the separation distance between the radiator and the reflector; and
wherein the vessel is configured such that the volume of the vessel is based on ambient pressure, thereby causing the separation distance to be based, at least in part, on the ambient pressure.