Array Antenna Calibration via Dedicated Signal Path

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Solution Overview

Problem

Existing array antenna calibration methods fail to account for changes in directivity and side lobe characteristics caused by thermal effects and environmental changes, especially in satellite systems where real-time calibration is challenging due to operational communication constraints.

Innovation Solution

A calibration device and method that calculates weighting coefficients based on real-time signal processing of input signals from array antennas, using a correlation matrix and eigenvalue decomposition to determine necessary calibration adjustments, allowing for parallel operation with communication functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If calibration is performed using conventional methods (Patent Literatures 1-3), then mutual coupling between antennas can be corrected, but calibration cannot be performed when communication function is operating due to thermal effects and environmental changes

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcommunication continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system separates calibration signal processing from communication signal processing by providing dedicated calibration signal input terminals and a specific calibration signal input unit. This segmentation allows calibration to occur independently without interfering with ongoing communication operations, resolving the contradiction between maintaining calibration accuracy and ensuring communication continuity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A dedicated calibration signal is introduced as an intermediary to enable calibration during communication operations. This calibration signal, input through separate terminals and processed by a specific calibration signal input unit, acts as a mediator that allows the system to perform calibration without using communication signals, thus maintaining both calibration accuracy and communication continuity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If real-time calibration is performed during communication operations, then environmental changes can be compensated, but system complexity increases

Engineering Contradiction:
Improvedirectivity characteristics stabilityVSAvoidcalibration system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The calibration function is extracted and implemented through a dedicated calibration signal input unit and separate calibration signal terminals, rather than attempting to perform calibration using existing communication signal paths. This extraction approach enables real-time calibration during communication operations by using a simplified, purpose-built calibration path, thus improving directivity stability without proportionally increasing overall system complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If thermal effects are compensated for in satellite systems, then directivity characteristics can be maintained, but calibration must interrupt communication function

Engineering Contradiction:
Improveantenna performance consistencyVSAvoidcommunication interruption time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system enables continuous calibration during communication operations by providing a dedicated calibration signal input unit and separate calibration terminals. This allows the calibration function to operate continuously without interrupting communication, maintaining antenna performance consistency while avoiding communication interruptions. The useful actions of both calibration and communication continue simultaneously through separate signal paths.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP2602631B1Calibration device and calibration method for array antenna
Publication Date: 2019.06.12 NEC CORP
  • EP2602631B1 patent drawingFigure 1
  • EP2602631B1 patent drawingFigure 2
  • EP2602631B1 patent drawingFigure 3

AI summary

In order to perform calibration of respective systems of an array antenna with high accuracy for adapting to a change in environmental condition, provided is a calibration device (20A) for calibrating an array antenna mounted on a satellite or the like, the calibration device including: a calibration coefficient calculating unit (21) to calculate a correlation of a plurality of input signals Xi(t,P), which are obtained by performing predetermined signal processing for signals received by an array antenna (11), to calculate weighting coefficients (βW) for calibrating systems of the array antenna; and a calibration executing unit (27) to calibrat the systems of the array antenna based on the weighting coefficients (βW).