DBF Antenna Array Self-Calibration for Fast Phase and Gain Alignment

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Solution Overview

Problem

Existing methods for calibrating electronically steered antennas (ESAs) are time-consuming and require expensive, specialized test equipment, making them inefficient and costly.

Innovation Solution

A system and method for calibrating a digital beam forming (DBF) antenna array that simultaneously transmits a set of calibration signals on multiple antenna radiating elements, using a first processor to measure phase and gain, and calibrating the elements using estimated relative phase and gain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If standard transmit ESA calibration methods are used, then calibration accuracy is achieved, but calibration time is excessive and equipment cost is high

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The antenna array performs self-calibration by having each antenna element transmit calibration signals and receive signals from other elements. The receive device processes these signals to determine phase and gain offsets, eliminating the need for external specialized calibration equipment and reducing calibration time while maintaining accuracy.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical positioning systems and specialized test equipment with a signal-processing-based calibration approach. By using digital signal processing to analyze calibration signals transmitted between antenna elements, the system achieves accurate calibration without mechanical intervention or expensive specialized equipment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If standard transmit ESA calibration methods are used, then calibration accuracy is achieved, but equipment complexity and cost increase

Engineering Contradiction:
Improvecalibration accuracyVSAvoidequipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The antenna array serves its own calibration needs by having elements transmit and receive calibration signals among themselves. This self-service approach eliminates the requirement for external calibrated signal sources, spectrum analyzers, and other specialized test equipment, thereby reducing equipment complexity and cost while maintaining calibration accuracy.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The receive device performs multiple functions: it receives calibration signals from antenna elements, processes these signals to determine phase and gain offsets, and outputs calibration results. This multi-functional approach eliminates the need for separate specialized calibration instruments, reducing overall equipment complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If simultaneous calibration signals are transmitted on multiple antenna elements, then calibration speed improves, but signal coordination complexity increases

Engineering Contradiction:
Improvecalibration speedVSAvoidsignal coordination complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The receive device receives calibration signals from multiple antenna elements simultaneously and processes these signals to determine phase and gain offsets. This feedback mechanism allows the system to coordinate multiple simultaneous transmissions by having the receive device analyze the combined signals and extract calibration information, thereby achieving fast calibration without excessive coordination complexity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system transmits calibration signals on multiple antenna elements simultaneously rather than sequentially. This preliminary action of parallel signal transmission significantly speeds up the calibration process. The receive device is pre-configured to handle and process these simultaneous signals, managing the coordination complexity through designed signal processing algorithms.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4496239A1System and method for calibrating transmit antenna array
Publication Date: 2025.01.22 ROCKWELL COLLINS INC
  • EP4496239A1 patent drawingFigure 1A
  • EP4496239A1 patent drawingFigure 1B
  • EP4496239A1 patent drawingFigure 1C

AI summary

A system may include a digital beam forming (DBF) antenna array (102) including antenna radiating elements (104) including a first and second antenna radiating elements. The DBF antenna array may be configured to: simultaneously transmit a set of calibration signals on multiple antenna radiating elements, the multiple antenna radiating elements including the first and second antenna radiating elements, each calibration signal of the set of calibration signals comprising a given timing acquisition sequence and a given second sequence, the given second sequence used to measure a phase and a gain of a given antenna radiating element; transmit a first calibration signal of the set by the first antenna radiating element; transmit a second calibration signal of the set by the second antenna radiating element; and calibrate the multiple antenna radiating elements by using an estimated relative phase and an estimated relative gain for each of the multiple antenna radiating elements.