Multi-Polarized Phased Array Antenna Isolation via Phase Shifters
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Solution Overview
Problem
Existing antenna designs face challenges in achieving high gain in a small area while maintaining sufficient isolation between differently polarized signals, particularly in phased array and dish feed antennas.
Innovation Solution
A multi-polarized scanning phased array antenna is designed with a configuration that includes multiple elements, horizontal and vertical feed lines, and phase delays to cancel polarized signals, utilizing phase shifters and additional conductor lengths to achieve 180° phase shifts and other phase shifts for elevation and azimuth scanning, allowing for increased isolation between polarizations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple elements are used to provide high gain in a small area, then the gain increases, but the isolation between differently polarized signals deteriorates
Solution Approach 1:
The antenna element is segmented into multiple feed points (first, second, third, and fourth feed points) that are spatially separated. Each feed point is connected to separate feed lines (first and second feed lines) that carry differently polarized signals. This segmentation allows the element to handle multiple polarizations simultaneously while maintaining isolation between them through the spatial separation and dedicated feed paths.
Solution Approach 2:
The patent introduces feed lines as intermediary components that connect the antenna element to the signal sources. The first feed line carries a first polarized signal and the second feed line carries a second polarized signal. These intermediary feed lines provide isolation between the different polarizations by physically separating the signal paths, preventing direct interference between differently polarized signals while still allowing the single antenna element to receive both polarizations.
2Device complexity
If a single element is used for both polarizations, then the device complexity reduces, but the isolation between polarizations deteriorates
Solution Approach 1:
The single antenna element is designed to perform multiple functions by receiving both first and second polarized signals simultaneously. The element is fed at multiple feed points (first, second, third, and fourth feed points) that allow it to handle different polarizations. This multi-functionality is achieved without requiring separate antenna elements for each polarization, thus reducing device complexity while maintaining signal isolation through the multi-feed-point architecture.
Solution Approach 2:
The patent transitions from a single-feed-point architecture to a multi-feed-point architecture, adding the dimension of spatial distribution within the single element. The feed points are positioned at different locations on the element (e.g., opposite sides or corners), creating a two-dimensional distribution of feed points. This dimensional change allows the single element to accommodate multiple polarizations with proper isolation by exploiting the spatial relationships between feed points.
3Object-affected harmful factors
If phase delays are added to cancel polarized signals, then the isolation between polarizations improves, but the device complexity increases
Solution Approach 1:
The patent employs phase delay components that introduce specific phase shifts (e.g., 90-degree or 180-degree phase shifts) to the signals in the feed lines. By changing the phase parameter of the signals, the patent enables destructive interference of unwanted polarized signals at specific receive ports, thereby improving isolation between polarizations. The phase delay can be implemented through physical path length differences or phase-shifting components in the feed lines.
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
The solution effectively increases isolation between polarizations, enabling one element to be used for both polarizations simultaneously without cancellation or attenuation issues, achieving complete or near-complete isolation in various scanning configurations.
Implementation Method 1
The phase delay is configured to cancel a polarized signal associated with the multi-polarized scanning phased array antenna. At least one of the first and second phase delays may include a 180° phase shift.
Implementation Method 2
The first feed line may be configured to at least one of transmit and receive at least one of a vertically polarized signal, horizontally polarized signal, right-hand clockwise circularly polarized signal, and left-hand counterclockwise circularly polarized signal.
Data Source
AI summary
A multi-polarized scanning phased array antenna is provided, which includes a first element, second element, first feed line, second feed line, first 180 degree phase shifter, second 180 degree phase shifter, third 180 degree phase shifter, fourth 180 degree phase shifter, Θ1 degree phase shifter, and Θ2 degree phase shifter. The first element is fed with a first polarization signal at a first feed point and a third feed point, and a second polarization signal at a second feed point and a fourth feed point. The second element is fed with the first polarization signal at a fifth feed point and a seventh feed point, and the second polarization signal at a sixth feed point and an eighth feed point. The first feed line is coupled to the elements and associated with the first polarization. The second feed line is coupled to the plurality of elements and associated with the second polarization. The first 180 degree phase shifter is coupled in the first feed line between the first and third feed points, and the second 180 degree phase shifter is coupled in the second feed line between the second and fourth feed points. The third 180 degree phase shifter is coupled in the first feed line between the fifth and seventh feed points, and the fourth 180 degree phase shifter is coupled in the second feed line between the sixth and eighth feed points. The Θ1 degree phase shifter is coupled in the first feed line between the third and seventh feed points, and the Θ2 degree phase shifter is coupled in the second feed line between the second and sixth feed points.