System and method for aligning signals having different phases

• US 6,515,616 B1
• Filed: 04/30/1999
• Issued: 02/04/2003
• Est. Priority Date: 04/30/1999
• Status: Expired due to Term

• Current Assignee: Kathrein SE
• Original Assignee: Metawave Communications Corp.
• Inventors: Kuplicki, Michael G.
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US09/303,075
• Time in Patent Office: 1,376 Days
• Field of Search: 342/165, 342/169, 342/170-175, 342/195, 342/368, 342/371, 342/372, 342/369, 342/370, 342/373-377, 342/73-103
• US Class Current: 342/174
• 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: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H04B 7/084 Equal gain combining, only phase adjustments antenna beam scanning or forming by phase or amplitude control H01Q3/26, e.g. phased arrays

Abstract

A system and method for changing the phase relationship of input signals so as to generate a composite signal having the strongest possible signal. One related input vector signal is phase rotated and a phase is selected which yields the smallest value of the output composite signal. The selected phase is rotated 180 degrees. This procedure for that input signal is repeated for each input vector signal. When all inputs have thus been adjusted, the procedure can be repeated until the output composite signal is essentially free of errors.

Claims

1. A method for aligning input signals of a composite signal where the input signals each comprise a vector having a particular phase, the method comprising the steps of

determining a phase rotation of a first one of said vectors such that the composite signal is determined to be at its minimum value for such phase rotation;

rotating the phase from the determined phase rotation of said first one of said vectors a specific amount; and

repeating said determining and rotation steps for at least some of the other vectors.

2. The method of claim 1 wherein said specific amount of said rotation is 180 degrees.

3. The method of claim 1 wherein said determining and rotating steps are repeated for all of said vectors.

4. The method of claim 3 wherein said determining and rotating steps are again repeated vector by vector until a degree of error in the composite signal within a predetermined range is achieved.

5. The method of claim 1 where the composite signal is generated at a location physically remote from the input signals.

6. The method of claim 1 where the signals pass from the input signal vectors to the composite signal over different signal paths, each having different signal characteristics, and wherein the phase adjustment is made prior to the signals being applied to said signal paths.

7. The method set forth in claim 6 where the input signals are at a base station and the composite signal is generated at an antenna array.

8. A system for aligning input signals of a composite signal where the input signals comprise vectors, the system comprising:

a null detector for determining a phase rotation of each phase vector of said signal vectors, one at a time, such that the composite signal is determined to be at its minimum value for each such vector phase rotation; and

a phase reversal circuit for reversing the determined phase rotation of each of said phase vectors.

9. A system as set forth in claim 8 where the composite signal is generated physically remote from the input signals.

10. A system as set forth in claim 9 where the signals pass from the input signal vectors to the composite signal over different signal paths, each having different signal characteristics.

11. A system for aligning input signals of a composite signal where the input signals each comprise a vector having an adjustable phase, the system comprising

means for determining a phase rotation of each of said vectors, one at a time, such that the composite signal is determined to be at its minimum value for each such vector phase rotation;

and

means for reversing the determined phase rotation of each of said vectors.

12. A system for providing signals to a combiner for communication of a composite signal to an antenna wherein said provided signals must have a relatively small phase differential thereinbetween and wherein said provided signals are communicated to said antenna array from a remote location over communication paths which introduce varying amounts of phase change to the respective signals, said system comprising:

a phase adjuster for adjusting the phase of one of said provided signals such that the composite signal has a minimum value; and

a phase rotation for changing the adjusted phase, said one provided signal by 180 degrees.

13. The system of claim 12 further including:

a phase adjuster for adjusting the phase, in turn, of each of the other said provided signals such that the composite signal for each such adjustment has a minimum value; and

a phase rotator for changing the adjusted phase of each of said provided signals by 180 degrees.

14. A phased array antenna system having a plurality of individual antennas arranged to simultaneously broadcast a signal such that a phase relationship of the signal as it appears at each such individual antenna determines a coverage area of the resultant signal, wherein said phased array is adapted to provide self-contained tuning of the phase of said signal as it appears at each individual antenna to maintain said phase relationship, said system comprising:

means for communicating to each such individual antenna the signal, thereby providing a communicated signal to each such individual antenna having a desired phase;

means for monitoring a magnitude of the signal actually received at each such antenna;

means controlled by said monitoring means for adjusting the phase of a first one of said communicated signals until the magnitude is monitored as being minimum as actually received at each said antenna;

means controlled by said adjusting means for rotating said adjusted phase by 180 degrees;

means controlled by said monitoring means for adjusting the phase of other ones of said communicated signals, one at a time, until the magnitude is monitored as being minimum for each such adjustment; and

means controlled by said last-mentioned adjusting means for rotating, in turn, each of said adjusted phases by 180 degrees.

15. A method for providing signals to a combiner for communication of a composite signal to an antenna wherein said provided signals must have a relatively small phase differential thereinbetween and wherein said provided signals are communicated to said antenna array from a remote location over communication paths which introduce varying amounts of phase change to the respective signals, said method comprising the steps of:

adjusting the phase of one of said provided signal s such that said composite signal has a minimum value; and

changing the adjusted phase of said one provided signal by 180 degrees.

16. The method of claim 15 further including the steps of:

adjusting the phase, in turn, of each of the other said provided signals such that said composite signal for each such adjustment has a minimum value; and

changing the adjusted phase of each of said provided signals by 180 degrees.