Tri-pole Antenna Element for Compact Dual-Polarized Arrays
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Solution Overview
Problem
Existing multiband antennas face challenges in achieving compact size and reducing cost while maintaining +/-45 degree polarization, as conventional radiating elements often suffer from undesirable coupling and increased size, which can lead to physical and zoning constraints.
Innovation Solution
The use of tri-pole radiating elements with a first and second side arm and a center arm perpendicular to them, oriented such that either the side arms or the center arm are parallel to the longitudinal axis of the reflector, along with a feed network for signal paths, allows for compact dual-polarized and multiband operation with reduced coupling and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional crossed dipole elements are used for +/-45 degree polarization, then the desired polarization diversity is achieved, but the antenna size increases and coupling between elements occurs
Solution Approach 1:
The conventional crossed dipole element is segmented into three separate arms (first side arm, second side arm, and center arm) that are fed independently. This segmentation allows each arm to be optimally positioned and fed, reducing the overall element size while maintaining polarization diversity through the three-dimensional arm configuration.
Solution Approach 2:
The patent introduces a third spatial dimension by adding a center arm perpendicular to the side arms, creating a three-dimensional radiating structure. This dimensional change enables compact +/-45 degree polarization without requiring large planar spacing, as the polarization is achieved through 3D arm orientation rather than 2D element spacing.
2Reliability
If radiating elements are spaced further apart to reduce coupling, then coupling between elements is reduced, but the antenna width increases
Solution Approach 1:
By segmenting the dipole into three independently fed arms, the patent achieves better element isolation through the 3D spatial separation of current paths while maintaining compact planar dimensions. The segmented structure allows each arm to radiate with reduced mutual coupling.
Solution Approach 2:
The patent creates a composite radiating structure combining three arms with different orientations and feed points. This composite configuration provides both isolation (through spatial separation of current distributions) and compactness (through integrated 3D geometry).
3Adaptability or versatility
If multiple radiating elements for different bands are combined on a single panel, then multiband operation is achieved, but the panel width and wind loading increase
Solution Approach 1:
The tri-pole radiating element is designed as a universal structure that can operate across multiple frequency bands by adjusting feed impedances and arm dimensions. This multi-functional element eliminates the need for separate dedicated elements for each band, reducing overall antenna width and associated wind loading.
Solution Approach 2:
The patent merges multiple band operations into a single integrated tri-pole element rather than using separate elements for each band. This consolidation achieves multiband functionality while minimizing the total panel area and reducing wind loading compared to multiple separate element assemblies.
4Ease of manufacture
If conventional dipole elements are used, then simple construction is maintained, but +/-45 degree polarization with compact size cannot be achieved
Solution Approach 1:
The dipole is segmented into three arms that can be manufactured as separate components and assembled, or formed as a single integrated structure. This segmentation enables compact +/-45 degree polarization while maintaining manufacturing simplicity through modular construction or standard fabrication processes.
Data Source
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AI summary
A dual polarized base station antenna is provided, including a reflector having a longitudinal axis and an array of tri-pole elements disposed on the reflector. Each tri-pole element has a first side arm and a second side arm. The tri-pole element also includes a center arm which is approximately perpendicular to the first and second side arms. The tri-pole elements are oriented such that either the side arms or the center arm are parallel to the longitudinal axis of the reflector. The antenna further includes a feed network having a first signal path coupled to the first arms of the tri-pole elements and a second signal path coupled to the second anus of the tri-pole elements. In this example, the array of tri-pole elements produces a cross-polarized beam at +45 degrees and −45 degrees from the longitudinal axis. Tri-pole arrays may be used in a multiband antenna.