Beamformer for multi-beam broadcast antenna

• US 7,109,919 B2
• Filed: 09/03/2004
• Issued: 09/19/2006
• Est. Priority Date: 11/09/2001
• Status: Active Grant

• Current Assignee: EMS Technologies, Inc. (Honeywell International Inc.)
• Original Assignee: EMS Technologies, Inc. (Honeywell International Inc.)
• Inventors: Howell, James M.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US10/934,235
• Publication Number:
  US 20050128141A1
• Time in Patent Office: 746 Days
• Field of Search: 342/372, 342/377, 455/456.1
• US Class Current: 342/372
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity

Abstract

A phased array antenna system operative to broadcast multiple beams that each include coded data for specific users located within the coverage area of the corresponding beam. An appropriate receiver then receives and decodes a particular beam to extract the specific data for a corresponding user. Multiple users may be assigned to each beam using frequency division or orthogonal code multiplexing, and the user data may be encoded into the beams using frequency shift key or phase shift key encoding. For each coding technique, the encoded antenna control signals are combined into a total gain and total phase shift control signal, which drives a single phase and gain control device for each antenna element. In addition, a single data modulator generates the coding parameters for the entire communication system.

Claims

1. A multi-beam phased array antenna system comprising:

a plurality of antenna elements;

a single phase and gain control device associated with each antenna element; and

a beam forming computer configured to generate control signals to drive the phase and gain control devices to create multiple beams, wherein;

each beam is assigned unique data corresponding to each of a plurality of users located within a coverage associated with the corresponding beam,

a control signal for each antenna element comprises a total gain and a total phase shift, and

the control signal for each antenna element comprises a vector sum of beam components in which one beam component corresponds to each beam, and each beam component comprises a vector sum of unique data signals assigned to each of a plurality of users assigned to the corresponding beam, to encode each beam with the unique data assigned to each user located within the coverage area of the associated beam to enable each user assigned to each beam to engage in a unique communication.

2. The antenna system of claim 1, wherein each data signal comprises a coding parameter representing the unique data for an associated user.

3. The antenna system of claim 1, wherein:

the control signal for each antenna element comprises an in-phase component defined by a sum of in-phase beam components for the corresponding antenna element;

the control signal for each antenna element comprises a quadrature component defined by a sum of quadrature beam components for the corresponding antenna element; and

the control signal for each antenna element comprises a total gain and a total phase shift for the antenna element based on the in-phase and quadrature components for the corresponding antenna element.

4. The antenna system of claim 3, wherein:

the in-phase beam components for each antenna element includes an in-phase component corresponding to each beam; and

the quadrature beam components for each antenna element includes a quadrature component corresponding to each beam.

5. The antenna system of claim 4 wherein the beam forming computer is configured to embed coding parameters in the in-phase and quadrature beam components.

6. The antenna system of claim 5, wherein:

the beam forming computer is configured to assign multiple users to each beam using frequency division multiplexing; and

the beam forming computer is configured to encode the user data into each beam using a frequency shift key coding technique.

7. The antenna system of claim 5, wherein:

the beam forming computer is configured to assign multiple users to each beam using frequency division multiplexing; and

the beam forming computer is configured to encode the user data into each beam using a phase shift key coding technique.

8. The antenna system of claim 5, wherein:

the beam forming computer is configured to assign multiple users to each beam using orthogonal multiplexing; and

the beam forming computer is configured to encode the user data into each beam using a phase shift key coding technique.

9. The antenna system of claim 5, wherein the beam forming computer is configured to encode the user data into each beam using coding parameters that are changed on demand.

10. A multi-beam phased array antenna system comprising:

a plurality of antenna elements;

a phase and gain control device associated with each antenna element; and

a continuous wave source;

a splitter for receiving an input carrier signal from the continuous wave source, dividing the input carrier signal into a plurality output carrier signals, and delivering an output carrier signal to each antenna element and associated phase and gain control device;

a beam forming computer configured to generate control signals to drive the phase and gain control devices to create multiple beams, wherein the control signal for each antenna element includes a beam component corresponding to each beam; and

wherein the beam forming computer is configured to generate a control signal for each antenna element that comprises a vector sum of beam components in which one beam component corresponds to each beam, and each beam component comprises a vector sum of unique data signals assigned to each of a plurality of users assigned to the corresponding beam, to encode each beam with the unique data assigned to each user.

11. The antenna system of claim 10, wherein each beam component comprises a total gain and a total phase shift reflecting a vector sum of beam components in which each bean components corresponds to an associated beam.

12. The antenna system of claim 11, comprising a single phase and gain control device associated with each antenna element, a single continuous wave source, a single splitter, and a single beam forming computer.

13. The antenna system of claim 12, wherein:

the control signal for each antenna element comprises an in-phase component defined by a sum of in-phase beam components for the corresponding antenna element; and

the control signal for each antenna element comprises a quadrature component defined by a sum of quadrature beam components for the corresponding antenna element; and

the control signal for each antenna element comprises a total gain and a total phase shift for the antenna element based on the in-phase and quadrature components for the corresponding antenna element.

14. The antenna system of claim 13, wherein:

the in-phase beam components for each antenna element includes an in-phase component corresponding to each beam; and

the quadrature beam components for each antenna element includes a quadrature component corresponding to each beam.

15. The antenna system of claim 14 wherein the beam forming computer is configured to embed coding parameters in the in-phase and quadrature beam components.

16. The antenna system of claim 15, wherein:

the beam forming computer is configured to assign multiple users to each beam using frequency division multiplexing; and

the beam forming computer is configured to encode the user data into each beam using a frequency shift key coding technique.

17. The antenna system of claim 15, wherein:

the beam forming computer is configured to assign multiple users to each beam using frequency division multiplexing; and

the beam forming computer is configured to encode the user data into each beam using a phase shift key coding technique.

18. The antenna system of claim 15, wherein:

the beam forming computer is configured to assign multiple users to each beam using orthogonal multiplexing; and

the beam forming computer is configured to encode the user data into each beam using a phase shift key coding technique.

19. The antenna system of claim 15, wherein the beam forming computer is configured to encode the user data into each beam using coding parameters that are changed on demand.

20. In or for a beam former operative for controlling a phased array antenna system including a plurality of antenna elements, a phase and gain control device associated with each antenna element, a continuous wave source, and a splitter for receiving an input carrier signal from the continuous wave source, dividing the input carrier signal into a plurality output carrier signals and delivering one of the output carrier signals to each antenna element and associated phase and gain control device, an improvement comprising:

a beam forming computer operative for coding unique data assigned to each of a plurality of users assigned to each of a plurality of beams and combining the coded data into control signals to drive the plurality of antenna elements to broadcast the beams to enable each user assigned to each beam to engage in a unique communication, wherein the beam forming computer is configured to generate a control signal for each antenna element that comprises a vector sum of beam components in which one beam component corresponds to each beam, and each beam component comprises a vector sum of unique data signals assigned to each of a plurality of users assigned to the corresponding beam.

21. The beam former of claim 20, wherein the control signal for each antenna element comprises a vector sum of beam components in which one beam component corresponds to each beam.

22. The antenna system of claim 20, comprising a single phase and gain control device associated with each antenna element, a single continuous wave source, a single splitter, and a single beam forming computer.