Phased Array Antenna Phase Calibration via Power Pattern Analysis
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Solution Overview
Problem
Existing phased array antennas face challenges in accurately calibrating the phase of antenna elements due to low received power when only one element is changed, leading to imprecise phase calibration.
Innovation Solution
A phased array antenna system that uses a reference and target antenna element to generate and receive radio waves, obtaining a power variation pattern by changing the phase of the target antenna element while the reference's phase is fixed, and setting the calibration value to 180° of the phase where the received power becomes minimal, allowing for precise phase alignment across all elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If only one antenna element is changed during calibration, then the calibration process is simple, but the received power is low making it difficult to precisely obtain phase correlation
Solution Approach 1:
The patent combines multiple antenna elements (reference element and target element) to work together during calibration. By radiating radio waves from both elements simultaneously and measuring the combined received power at the receiver, the system achieves sufficient received power for precise measurement while maintaining calibration simplicity. This merging approach resolves the contradiction by allowing accurate phase correlation measurement without requiring complex multi-element configurations.
2Measurement precision
If multiple antenna elements are used for calibration, then received power increases improving measurement precision, but the calibration process becomes more complex
Solution Approach 1:
The patent segments the calibration process into a systematic sequence: selecting a reference antenna element, then sequentially selecting each target antenna element for calibration. This segmentation allows the use of multiple antenna elements for improved measurement precision while maintaining process simplicity through structured, step-by-step calibration. Each element is calibrated individually against the reference, avoiding the complexity of simultaneous multi-element calibration.
Solution Approach 2:
The patent performs preliminary selection of a reference antenna element before conducting the actual phase calibration measurements. This preliminary action establishes a stable reference point that simplifies subsequent measurements. By pre-defining the reference element and its phase relationship, the system achieves precise phase measurement using multiple elements without introducing unnecessary complexity into the calibration workflow.
3Power
If radio waves are radiated from multiple antenna elements, then received power at the receiver increases, but it becomes difficult to obtain accurate phase correlation
Solution Approach 1:
The patent uses feedback from the received power measurement to determine phase correlation accuracy. By measuring the received power at the receiver and analyzing its relationship with the phases of the reference and target antenna elements, the system can accurately determine phase correlation. The feedback mechanism allows the system to achieve both high received power and accurate phase correlation measurement by adjusting phases based on measured power levels.
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 enables accurate and simplified phase calibration of all antenna elements by leveraging the difference in power patterns between adjacent elements, improving calibration precision and reducing the complexity of the calibration process.
Implementation Method 1
a phase shifter that is connected to each of the plurality of antenna elements and changes a phase of radio waves radiated by the plurality of antenna elements
Implementation Method 2
an oscillator that generates radio waves
Implementation Method 3
a receiver that receives radio waves radiated by the plurality of antenna elements
Data Source
AI summary
A phase array antenna includes an oscillator, a plurality of antenna elements, a phase shifter, a distributor, a receiving unit, and a control processor. The control processor performs a calibration process to select, from the antenna elements, a reference and target antenna elements to allow the radio waves generated by the oscillator to be provided for the reference and target antenna elements via the distributor, obtain a pattern of a change in a received power of radio waves received at the receiving unit, when a phase of the phase shifter for the reference antenna element is fixed and a phase of the phase shifter for the target antenna element is changed, extract, from the pattern obtained, the phase of the phase shifter for the target antenna element at which the received power becomes a local minimal value, and add the phase extracted to 180° to set its resultant value to a calibration value for the phase of the phase shifter for the target antenna element.