Steerable antenna assembly utilizing a dielectric lens

Patent metadata

Field	Value
Publication number	US-9979459-B2
Application number	US-201615379228-A
Country	US
Kind code	B2
Filing date	Dec 14, 2016
Priority date	Aug 24, 2016
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A steerable antenna assembly (“SAA”) for receiving a plurality of incident radio frequency (“RF”) signals at a plurality of incident angles is disclosure. The SAA includes an approximately spherical dielectric lens (“SDL”), a waveguide aperture block (“WAB”), a switch aperture matrix (“SAM”), and a radial aperture combiner (“RAC”). The SDL receives and focuses the plurality of incident RF signals creating a plurality of focused RF signals at a plurality of focal points approximately along the back surface of the SDL. The WAB is positioned adjacent to the back surface of the SDL and receives the plurality of focused RF signals. The SAM electronically steers a beam of a radiation pattern produced by the SAA and switch between the pluralities of focused RF signals based on electronically steering the beam. The RAC produces a received RF signal from the plurality of focused RF signals.

First claim

What is claimed is:

1. A steerable antenna assembly “SAA” for receiving a plurality of incident radio frequency “RF” signals at a plurality of incident angles, the SAA comprising:
an approximately spherical dielectric lens “SDL” having
a front surface and
a back surface, the SDL being operable to receive and focus the plurality of incident RF signals to create a plurality of focused RF signals at a plurality of focal points approximately along the back surface of the SDL, the plurality of focal points having positions along the back surface of the SDL that correspond to the plurality of incident angles of the plurality of incident RF signals;

a waveguide aperture block “WAB” positioned adjacent to the back surface of the SDL, the WAB being in signal communication with the back surface of the SDL, the WAB being operable to receive the plurality of focused RF signals;
a switch aperture matrix “SAM” in signal communication with the WAB, the SAM being operable to electronically steer a beam of a radiation pattern produced by the SAA, the SAM being operable to switch between the plurality of focused RF signals based on electronically steering the beam; and
a radial aperture combiner “RAC” in signal communication with SAM, the RAC being operable to produce a received RF signal from the plurality of focused RF signals.

2. The SAA of claim 1 , wherein the SDL has at least one of:
a shape that is approximately a sphere or an oblate spheroid;
a sphericity variation that is less than approximately 0.01 wavelength of an operating RF frequency of the SAA;
a diameter of approximately 152.4 mm;
a dielectric constant approximately between 2 and 5; and
a gradient of decreasing refractive index radially out from a center of the SDL.

3. The SAA of claim 2 , wherein the SDL consists of a material selected from the group consisting of a thermoset plastic, a polycarbonate, a cross-linked polystyrene copolymer, and Polytetrafluoroethylene “PTFE”.

4. The SAA of claim 2 , wherein the SDL is a Luneburg lens.

5. The SAA of claim 1 , wherein the WAB includes
a concave inner surface positioned adjacent to the back surface of the SDL and
a conformal aperture array antenna “CAA” along the concave inner surface,
wherein the CAA is in signal communication with the back surface of the SDL and
wherein the CAA includes a plurality of aperture elements.

6. The SAA of claim 5 ,
wherein the WAB includes a plurality of waveguides in signal communication with the CAA,
wherein each waveguide of the plurality of waveguides includes a waveguide aperture in signal communication with the CAA, and
wherein each waveguide aperture of each waveguide of the plurality of waveguides corresponds to an aperture element of the plurality of aperture elements of the CAA.

7. The SAA of claim 6 ,
wherein each aperture element of the CAA is an elliptical aperture and
wherein each waveguide aperture of the each waveguide of the plurality of waveguides is a correspondingly elliptical aperture.

8. The SAA of claim 7 ,
wherein the each elliptical aperture element of the CAA is a circular aperture and
wherein each elliptical aperture of the each waveguide of the plurality of waveguides is a correspondingly circular aperture.

9. The SAA of claim 8 ,
wherein the plurality of waveguides includes a sub-plurality of waveguides and
wherein each waveguide of the sub-plurality of waveguides includes
a waveguide length,
a waveguide directional transition, and
a waveguide transition from the circular aperture to a rectangular waveguide.

10. The SAA of claim 9 ,
wherein the SDL has a center,
wherein each waveguide of the plurality of waveguides also includes a waveguide input-output “IO” port,
wherein each waveguide aperture is aligned with the center of the SDL,
wherein each waveguide IO port is aligned the other waveguide IO ports, and
wherein each waveguide IO port is in signal communication with the SAM.

11. The SAA of claim 10 , wherein each waveguide is a solid-state waveguide.

12. The SAA of claim 10 ,
wherein the SAM includes a plurality of selectively activated switches,
wherein each selectively activated switch of the plurality of selectively activated switches is in signal communication with a corresponding waveguide from the plurality of waveguides, and
wherein each selectively activated switch is configured to conduct, or block, a waveguide and output signal from the corresponding waveguide IO port to the RAC.

13. The SAA of claim 12 , wherein the each selectively activated switch includes a switching device selected from the group consisting of a PIN diode, latching ferrite switch, liquid crystal valve “LCV”, coaxial waveguide switch, and an RF isolator.

14. The SAA of claim 13 , further including a stepper motor operatively coupled with the WAB and configured to selectively rotate the WAB and SDL based on a control signal from a controller.

15. The SAA of claim 14 ,
wherein the RAC is a radial combiner in signal communication with each waveguide output port and
wherein the RAC is configured to produce the received RF signal with either left-hand circular polarization “LHCP” or right-hand circular polarization “RHCP”.

16. The SAA of claim 1 ,
wherein the SAA is a reciprocal device,
wherein the SDL produces a transmitted RF signal from a received input RF signal at the RAC,
wherein the transmitted RF signal has a transmitted beam of the radiation pattern, and
wherein the SAM is configured to electronically steer the transmitted beam.

17. The SAA of claim 1 , further including a radome disposed adjacent to the front surface of the SDL.

18. A method for receiving a plurality of incident radio frequency “RF” signals at a plurality of incident angles with a steerable antenna assembly “SAA” the method comprising:
receiving the plurality of incident RF signals at a front surface of an approximately spherical dielectric lens “SDL;”
focusing the received plurality of incident RF signals to create a plurality of focused RF signals at a plurality of focal points approximately along a back surface of the SDL, wherein the plurality of focal points have positions along the back surface of the SDL that correspond to the plurality of incident angles of the plurality of incident RF signals;
receiving the plurality of focused RF signals at a waveguide aperture block “WAB” positioned adjacent to the back surface of the SDL;
switching between the plurality of focused RF signals based on electronically steering a beam of a radiation pattern produced by the SAA; and
combining the switched plurality of focused RF signals to produce a received RF signal with a radial aperture combiner “RAC.”

19. The method of claim 18 , wherein switching includes conducting or blocking a plurality of output signals, from a corresponding plurality of waveguide output ports, from the WAB to the RAC.

Assignees

• Boeing Co

Inventors

• Savage Larry L
• Thacker Corey M

Classifications

• H04B7/0874 Primary

  using subgroups of receive antennas · CPC title

• H01Q13/06

  Waveguide mouths (horns H01Q13/02) · CPC title

• H01Q3/34

  by electrical means (active lenses or reflecting arrays H01Q3/46) · CPC title

• H01Q1/241

  used in mobile communications, e.g. GSM (H01Q1/247, H01Q1/248 take precedence) · CPC title

• H01Q1/28

  Adaptation for use in or on aircraft, missiles, satellites, or balloons · CPC title