Antenna Calibration Matrix for Non-Symmetrical Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing antenna calibration methods rely on symmetry, which is not accurate for smaller antenna arrays with non-symmetrical elements, leading to suboptimal performance in wireless communication systems.
Innovation Solution
A method that involves transmitting signals from multiple reference antenna elements, measuring these signals in other elements, calculating correction values, and performing an optimization procedure using a correction matrix to improve calibration accuracy, regardless of symmetry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If symmetry-based calibration methods are used, then calibration is simple and works well for large arrays, but calibration accuracy deteriorates for smaller non-symmetrical arrays
Solution Approach 1:
The patent applies asymmetry by treating each antenna element individually rather than assuming symmetry. The calibration method calculates separate correction values for each element based on its unique position and coupling characteristics, eliminating the need for symmetry assumptions. This is achieved by measuring coupling between each reference element and all other elements, then computing element-specific correction values that account for non-uniform coupling in non-symmetrical arrays.
Solution Approach 2:
The patent changes the calibration parameters from symmetry-based correction factors to element-specific correction values derived from actual measured coupling data. The method introduces optimization parameters (weights) that are adjusted to minimize the difference between measured and expected coupling values, thereby adapting the calibration to the actual non-symmetrical configuration of the array.
2Measurement precision
If multiple reference antenna elements are used for calibration, then calibration accuracy improves, but measurement time and complexity increase
Solution Approach 1:
The patent segments the calibration process into multiple independent measurement stages, each using a different reference antenna element. Instead of performing one comprehensive measurement, the method divides the calibration into N separate measurements (where N is the number of antenna elements), with each measurement using one element as reference. This segmentation allows for more accurate element-specific correction values while enabling parallel processing and optimization of each measurement stage.
Solution Approach 2:
The patent applies partial action by selecting a subset of antenna elements as reference elements rather than requiring all elements to be measured in every configuration. The method uses each element as a reference in turn, performing measurements only with that reference element active, thereby reducing the total number of measurements compared to exhaustive calibration methods while still achieving complete coverage of all element pairs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method significantly enhances calibration accuracy for antenna systems of varying sizes, including non-symmetrical arrays, by reducing measurement errors and improving signal consistency across all elements.
Implementation Method 1
Calibration methods using mutual coupling are known, i.e. methods based on electromagnetic interaction between antenna elements in an antenna array
Data Source
AI summary
A method (20) of calibrating an antenna system (10) comprising a number of antenna elements is provided. The method (20) is performed in a control device (11) and comprises transmitting (21) a signal from a first reference antenna element selected among the antenna elements; measuring (22) the signal in two or more calibration antenna elements selected among the remaining antenna elements, and obtaining a first set of corresponding number of measurement values; repeating (23) the transmitting (21) and measuring (22) at least for a second reference antenna element different than the first reference antenna element, thereby obtaining a second set of corresponding number of measurement values, calculating (24) for each calibration antenna element j a correction value (A), based on the at least first and second sets of measurement values, thereby obtaining a correction matrix comprising for row i correction values for calibration antenna elements j relative antenna element k with antenna element i as the reference antenna element; performing (25) an optimization procedure using as input the correction matrix, wherein each column, except one, is multiplied with a respective constant Ci, thereby obtaining, for each row of the correction matrix, a respective optimized constant (B); and calculating (26) a correction value Δti for each antenna element based on the respective optimized constant (B). A control device, computer program and computer program products are also provided.