Phased array antenna systems with controllable electrical tilt

• US 20070080886A1
• Filed: 10/29/2004
• Published: 04/12/2007
• Est. Priority Date: 11/07/2003
• Status: Active Grant

• Current Assignee: Quintel Cayman Limited
• Original Assignee: Quintel Technology Limited (Cirtek Holdings Philippines Corp.)
• Inventors: Thomas, Louis, Haskell, Philip
• Granted Patent: US 7,420,507 B2
• Time in Patent Office: Days
• US Class Current: 343/824
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/06 Arrays of individually energised antenna units similarly polarised and spaced apart
• CPC Class Codes: H01Q 3/30 varying the relative phase between the radiating elements of an array H01Q3/2605, H01Q3/2658, H01Q3/2682, H01Q3/44 take precedence
• CPC Class Codes: H01Q 3/36 with variable phase-shifters
• CPC Class Codes: H01Q 3/40 with phasing matrix
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

A phased array antenna system with controllable electrical tilt generates two signals V2a and V2b with variable relative delay therebetween. The signals are converted into antenna element drive signals by a power distribution network. The network splits each of the two signals V2a and V2b into three signal components. Pairs of components of different signals are input respective hybrid coupling devices (hybrids), which provide vector sums and differences of their inputs and act as phase-to-power converters. Their outputs are distributed between further hybrids, which act as power-to-phase converters and provide antenna element drive signals with phase varying both with element array position and also with the variable relative delay between the two signals V2a and V2b. Antenna electrical tilt is therefore controllable by altering a single relative delay.

Claims

1. A phased array antenna system with controllable electrical tilt including:

a) an antenna with multiple antenna elements;

b) apparatus for providing two basis signals with variable relative delay therebetween,

c) splitting apparatus for dividing the basis signals into signal components,

d) phase to power converting apparatus for converting the signal components into transformed components having powers which vary as the relative delay varies, and

e) power to phase converting apparatus for converting the transformed components into antenna element drive signals having phases which vary from antenna element to antenna element progressively across the antenna when the antenna is electrically tilted and which individually vary as the relative delay varies.

2. A system according to claim 1 wherein the phase to power converting apparatus comprises a plurality of hybrid radio frequency coupling devices (“

hybrids”

) for providing sums and differences of pairs of signal components, each pair having signal components from both basis signals.

3. A system according to claim 1 wherein the phase to power converting apparatus comprises a plurality of 180 degree hybrids for providing sums and differences of pairs of signal components, each pair having signal components from both basis signals.

4. A system according to claim 3 wherein each pair has signal components of equal magnitude, but each pair'"'"'s component magnitude is not equal to that of another pair.

5. A system according to claim 3 wherein the hybrids are first hybrids and the power to phase converting apparatus incorporates a plurality of second hybrids arranged to generate antenna element drive signals.

6. A system according to claim 5 wherein the splitting apparatus is a first splitting apparatus and the power to phase converting apparatus incorporates a second splitting apparatus for dividing the sums and differences into components for input to the second hybrids.

7. A system according to claim 6 wherein the first splitting is for dividing each of the basis signals into three signal components.

8. A system according to claim 6 wherein the second splitting apparatus is a plurality of two-way splitters.

9. A system according to claim 1 wherein it is arranged such that all paths extending from basis signal provision to antenna elements contain the same numbers and types of components.

10. A method of controlling electrical tilt of a phased array antenna system including an antenna with multiple antenna elements, and wherein the method incorporates the steps of:

a) providing two basis signals with variable relative delay therebetween,

b) splitting the basis signals into signal components,

c) converting the signal components into transformed components having powers which vary as the relative delay varies, and

d) converting the transformed components into antenna element drive signals having phases which vary from antenna element to antenna element progressively across the antenna when the antenna is electrically tilted and which individually vary as the relative delay varies.

11. A method according to claim 10 wherein step c) is implemented using a plurality of hybrids for providing sums and differences of pairs of signal components, each pair having signal components from both basis signals.

12. A method according to claim 10 wherein step c) is implemented using a plurality of 180 degree hybrids providing sums and differences of pairs of signal components, each pair having signal components from both basis signals.

13. A method according to claim 12 wherein each pair has signal components of equal magnitude, but each pair'"'"'s component magnitude is not equal to that of another pair.

14. A method according to claim 12 wherein the hybrids are first hybrids and step d) is implemented using a plurality of second hybrids for generating the antenna element drive signals.

15. A method according to claim 14 wherein splitting in step b) is a first splitting and a second splitting is implemented in step d) to divide the sums and differences into components for input to the second hybrids.

16. A method according to claim 15 wherein the first splitting divides each of the basis signals into three signal components.

17. A method according to claim 15 wherein the second splitting is a plurality of two-way splits.

18. A method according to claim 10 including supplying antenna element drive signals to antenna elements via paths extending from basis signal provision and containing the same numbers and types of components.