Antenna Array Calibration Using Dummy Elements for Consistency
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Solution Overview
Problem
Conventional antenna array calibration methods using the air interface coupling feature primarily achieve reciprocity calibration, neglecting consistency calibration, which affects signal transmit power and fails to ensure consistency across the antenna array, leading to inefficiencies in broadcast beamforming.
Innovation Solution
The introduction of antenna dummy elements at both ends of the array allows for consistency calibration by ensuring similar coupling factors among adjacent antennas, aligning amplitude-phase responses through calibration compensation values calculated based on differences between antenna dummy elements and actual antennas, thereby implementing consistent calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional air interface coupling calibration method is used, then reciprocity calibration is achieved, but consistency calibration is neglected causing signal transmit power loss
Solution Approach 1:
The calibration process is segmented into two independent parts: reciprocity calibration and consistency calibration. The patent separates these functions by introducing dummy antennas specifically for consistency calibration, while existing antennas handle reciprocity calibration. This segmentation allows both calibration types to be performed without interfering with each other, resolving the contradiction between achieving reciprocity calibration and preventing signal power loss.
Solution Approach 2:
Dummy antennas are introduced as intermediary elements to enable consistency calibration without affecting the reciprocity calibration process. These dummy antennas serve as mediators that provide reference signals for calculating coupling factors and amplitude-phase responses, allowing consistency calibration to be performed independently while maintaining the benefits of reciprocity calibration.
2Productivity
If antenna quantity increases and hardware size decreases, then system throughput rate increases, but hardware design difficulty and algorithm complexity increase
Solution Approach 1:
The patent uses dummy antennas as simplified copies of actual antennas for calibration purposes. These dummy antennas replicate the essential coupling characteristics without requiring full functionality, reducing hardware complexity. The dummy antennas serve as reference copies that enable calibration of the entire antenna array without increasing the complexity of individual antenna elements.
Solution Approach 2:
The patent changes the calibration approach from direct measurement of all antenna parameters to measuring coupling factors between antennas. By focusing on coupling factor parameters rather than complete amplitude-phase characterization of each antenna, the algorithm complexity is reduced while still achieving accurate consistency calibration for large-scale antenna arrays.
3Ease of operation
If conventional calibration method is used, then calibration process is simplified, but consistency of antenna array cannot be calibrated
Solution Approach 1:
The patent performs preliminary calibration actions by having dummy antennas transmit and receive calibration signals before calculating the coupling factors. This preliminary action establishes reference measurements that simplify the subsequent consistency calibration process. The dummy antennas perform preliminary measurements of coupling factors, which are then used to calculate amplitude-phase responses for all antennas in the array.
Solution Approach 2:
The patent implements feedback by using the measured coupling factors to calculate and apply calibration coefficients that correct amplitude-phase inconsistencies. The system continuously monitors the coupling characteristics and adjusts the calibration parameters accordingly, providing feedback-based optimization that achieves high precision consistency calibration while maintaining operational simplicity.
Data Source
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AI summary
An antenna array calibration method and apparatus are provided. The method includes: when first target antennas in an antenna array transmit signals, and second target antennas in the antenna array receive the signals, calculating calibration compensation values of transmit channels in the first target antennas and calibration compensation values of receive channels in the second target antennas, so that amplitude-phase responses of the transmit channels in the first target antennas are consistent and amplitude-phase responses of the receive channels in the second target antennas are consistent after channel compensation; and when the second target antennas transmit signals, and the first target antennas receive the signals, calculating calibration compensation values of transmit channels in the second target antennas and calibration compensation values of receive channels in the first target antennas, so that amplitude-phase responses of the transmit channels in the second target antennas are consistent and amplitude-phase responses of the receive channels in the first target antennas are consistent after channel compensation. In embodiments of the present invention, an antenna dummy element or a radio frequency coupling component is added in the antenna array, so that amplitude-phase responses of transmit channels of all antennas are consistent, and amplitude-phase responses of receive channels of all the antennas are consistent, thereby implementing consistency calibration on the antenna array.