Portable apparatus and associated method for phased array field calibration

Patent metadata

Field	Value
Publication number	US-9614279-B2
Application number	US-201414456266-A
Country	US
Kind code	B2
Filing date	Aug 11, 2014
Priority date	Aug 11, 2014
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

A system for calibrating an array antenna comprises a calibration antenna at a first location relative to an array antenna, a first set of calibration files, and a processor. Based on received far field data from a far field data test that was run on the array antenna, using the calibration antenna, the processor is configured to generate a model predicting the actual location of the calibration antenna relative to the array antenna and to generate predicted far field data based on the model. The model is adjusted, if needed, by comparing the predicted far field data with the received far field data. Based on the model, new calibration files are generated that substantially correlate to the actual location of the calibration antenna.

First claim

The invention claimed is:

1. A system for calibrating an array antenna, the system comprising:
a calibration antenna positioned at a first location relative to the array antenna, and operably configured to be used as part of a far field test conducted on the array antenna, wherein the first location corresponds to an estimate of an actual location of the calibration antenna relative to the array antenna;
a first set of calibration files usable during at least one of calibration and operation of the array antenna; and
a processor in operable communication with the array antenna, the first set of calibration files and the calibration antenna, the processor accessing a memory storing instructions that, when executed, configure the processor to:
(a) generate a model of a predicted calibration configuration of the calibration antenna and the array antenna, the model based at least in part on the first location, the first set of calibration files, and a first set of received far field test data generated during a first far field data test run using the first set of calibration files, wherein the model defines a predicted calibration configuration comprising information related to a prediction of the actual location for the calibration antenna relative to the array antenna during the first far field calibration test;
(b) adjust the model, if necessary, based at least in part on comparing a set of predicted far field test data generated using the model with the first set of received far field test data, the adjustment of the model configured to decrease at least a portion of a difference between at least a portion of the predicted set of far field data and the corresponding portion of the first set of received far field data; and
(c) generate, based at least in part on the model, a second set of calibration files usable to replace at least a portion of the first set of calibration files.

2. The system of claim 1 , wherein the instructions further configure the processor to identify, based at least in part on at least one of the model, the first set of received far field test data, and the predicted set of far field test data, whether one or more hardware components of the antenna array require at least one of replacement and adjustment.

3. The system of claim 1 , wherein, if at least one hardware component of the antenna array is adjusted or replaced, the instructions further cause the far field data test to be repeated using the second set of calibration files in place of at least a portion of the first set of calibration files; to result in a second set of far field data, and wherein the instructions further configure the processor to repeat steps (a) through (c), using the second set of far field data and the second set of calibration flies, to adjust, if necessary, the first model, and to adjust, if necessary, the second set of calibration files.

4. The system of claim 1 , wherein the instructions further configure the processor to remove at least one outlier from the received far field data results before generating the first model.

5. The system of claim 1 , wherein the array antenna comprises a plurality of antenna elements and wherein the model is generated based at least in part using an assumption that a predetermined portion of the antenna elements having substantially good calibration.

6. The system of claim 1 , wherein the instructions further configure the processor to:
identify at least one outlier in first set of received far field test data, the outlier comprising at least one of an amplitude outlier, a phase outlier, and a frequency outlier; and
determine, based at least in part on the identified outlier, whether one or more hardware components that comprise the antenna array require either replacement or adjustment.

7. The system of claim 1 , wherein;
the prediction of the actual location comprises an approximate predetermined position, within a predetermined model range of positions; and
the model is based at least in part on determining a position, within the predetermined model range of position, where at least a portion of a set of received far field test data for that position best matches to a corresponding portion of predicted far field test data for that position.

8. A system for calibrating an array antenna, the system comprising:
a calibration antenna positioned at an actual location relative to an array antenna, the calibration antenna operably configured to be used as part of a far field test data test conducted on the array antenna;
a first set of calibration files usable during at least one of calibration and operation of the array antenna; and
a processor in operable communication with the first set of calibration files and further in operable communication with and operable control of the array antenna and the calibration antenna, wherein the actual location of the calibration antenna is not known to the processor, the processor accessing a memory storing instructions that, when executed, configure the processor to:
analyze a set of received far field data test generated during a far field data test, to determine if one or more data outliers exist and, if necessary, to remove at least one outlier from the far field test data results, to generate a set of processed received far field test data;
generate, based at least in part on the set of processed received far field test data, one or more curves that approximately match the set of processed received far field test data;
generate, based at least in part on the one or more curves, a first model corresponding to a second calibration configuration of the calibration antenna and array antenna, the second calibration configuration comprising information related to a predicted location for the calibration antenna, the predicated location corresponding substantially to the actual location of the calibration antenna during the far field data test;
generate, based at least in part on the first model, a set of predicted far field data results;
generate a second model for an actual position of the calibration antenna, the second model based at least in part on a comparison between at least a portion of the received far field data results and at least a portion of the set of predicted far field data results;
modify the second model, if necessary, to ensure that the at least a portion of the set of predicted far field test data correlate, within a predetermined threshold, with the set of processed received far field test data;
generate, based at least in part on the second model, a second set of calibration files usable during operation of the array antenna; and
replace at least a portion of the first set of calibration files with the second set of calibration files.

9. The system of claim 8 , wherein the instructions further configure the processor to:
identify at least one outlier in the set of received far field test data, the outlier comprising at least one of an amplitude outlier, a phase outlier, and a frequency outlier; and
identify, based at least in part on the identified outlier, at least one hardware component in the antenna array requiring either replacement or adjustment.

10. The system of claim 8 , wherein
the predicted location comprises an approximate predetermined position, within a predetermined model range of positions; and
at least one of the first and second models for the actual position of the calibration antenna is based at least in part on finding a position within the predetermined model range of positions, where at least a portion of the set processed received far field test data for that position best matches to a corresponding portion of predicted far field test data for that position.

Assignees

• Raytheon Co

Inventors

• Mcdevitt Thomas J
• Brennan David A
• Combs Curtis
• Hamner Christopher A
• Andrews Macdonald J
• Corn Joseph D

Classifications

• H01Q3/267 Primary

  Phased-array testing or checking devices · CPC title

• G01S13/91

  for traffic control (G01S13/93 takes precedence) · CPC title

• G01S2007/4082

  Physics · mapped topic

• G01S13/79

  Systems using random coded signals or random pulse repetition frequencies {, e.g. "Separation and Control of Aircraft using Non synchronous Techniques" [SECANT]} · CPC title

• G01S2013/0254

  Active array antenna · CPC title