Antenna reflector system
A scan range of a steerable antenna is extended using a reflecting surface or surfaces within the scan range. Various implementations may also include lenses, and the reflecting surface, lenses, or both may include meta-materials. The antenna may be steered to interact with the reflecting surface, lenses, or both to reflect the beam in a direction not possible using the antenna alone. The scan range may be extended in azimuth, elevation, or both, and beam pattern, and antenna freespace impedance may be controlled.
1. A millimeter wave (mmW) antenna system comprising:
a steerable planar antenna configured to produce a narrow beam with a scan range of less than 360 degree coverage;
a reflector configured to be positioned locally to the steerable planar antenna and at least partially within the scan range of the steerable planar antenna, wherein the reflector has a concave-down profile; and
the steerable planar antenna configured to be steered to point the narrow beam to reflect off different regions of the reflector to spread the narrow beam in azimuth to provide 360 degree coverage.
2. The mmW antenna system of claim 1 , wherein the planar antenna is an electrically steerable antenna.
3. The mmW antenna system of claim 1 , wherein the planar antenna is a mechanically steerable antenna.
4. The mmW antenna system of claim 1 , wherein the scan range is less than 90 degrees.
5. The mmW antenna system of claim 1 , wherein the steerable planar antenna is a phased array antenna (PAA).
6. The mmW antenna system of claim 1 , wherein the reflector is a fixed reflector.
7. The mmW antenna system of claim 1 , wherein the reflector has radial symmetry.
8. The mmW antenna system of claim 1 , wherein an axis of rotation of the reflector is parallel to a normal vector of the steerable planar antenna and intercepts the steerable planar antenna at its center.
9. The mmW antenna system of claim 1 , further comprising:
at least one lens in between the steerable planar antenna and the reflector configured to align the scan range of the steerable planar antenna with a solid angle projected by the reflector.
10. The mmW antenna system of claim 9 , wherein the at least one lens maps the narrow beam directed near a normal vector of the steerable planar antenna to points further away from the normal vector of the steerable planar antenna.
11. The mmW antenna system of claim 9 , wherein the at least one lens has radial symmetry.
12. The mmW antenna system of claim 1 , further comprising:
at least one lens around a perimeter of the reflector configured to align the scan range of the planar antenna for the reflector.
13. The mmW antenna system of claim 1 further comprising:
meta-material positioned on the reflector configured to modify a freespace impedance.
14. The mmW antenna system of claim 13 , wherein the meta-material is further configured to refine a beam pattern of the narrow beam.
15. The mmW antenna system of claim 13 , wherein the meta-material has a surface with a fractal pattern.
16. The mmW antenna system of claim 13 , wherein the meta-material includes gaps for shaping the narrow beam reflecting off the reflector.
17. The mmW antenna system of claim 1 , wherein the scan range of the narrow beam is extended in azimuth.
18. The mmW antenna system of claim 1 , wherein the scan range of the narrow beam is extended in elevation.
19. The mmW antenna system of claim 1 , wherein the scan range of the narrow beam is extended in both azimuth and elevation.
20. The mmW antenna system of claim 1 configured as a quasi-optical antenna system.