Cross-Dipole Feed Stalk Structure for Antenna Cloaking
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Solution Overview
Problem
Existing multi-band base station antennas face challenges in reducing width while minimizing interaction and scattering between radiating elements operating in different frequency bands, leading to distorted antenna patterns and performance issues.
Innovation Solution
The implementation of cross-dipole radiating elements with modified feed stalks, including short-circuited transmission lines, narrowed ground lines, and filter structures to suppress unbalanced currents and reduce metal content, thereby enhancing cloaking performance and minimizing interference between frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple arrays of radiating elements are used to support service in different frequency bands, then the capacity and service coverage are improved, but the antenna width increases and radiating elements interact with each other causing scattering and distorted antenna patterns
Solution Approach 1:
The patent extracts and removes portions of the feed stalk structure to create a cloaked feed stalk. Specifically, sections of the feed stalk are removed or narrowed to reduce the amount of metal present, thereby minimizing scattering of RF energy from adjacent radiating elements while maintaining the functional integrity of the feed stalk for delivering RF energy to the dipole radiators
Solution Approach 2:
The patent applies local quality by creating non-uniform feed stalk structures where different sections have different properties. The feed stalk includes narrowed portions or gaps at specific locations (such as at the boundaries between frequency bands) while maintaining full width in other sections, allowing the structure to be locally optimized to reduce scattering at critical interfaces between frequency bands
2Area of stationary object
If radiating elements are spaced closer together to reduce antenna width, then the antenna size is reduced, but interaction and scattering between radiating elements increases causing distorted antenna patterns
Solution Approach 1:
The patent converts the potentially harmful scattering effect into a beneficial cloaking effect. By strategically removing or narrowing feed stalk sections at interfaces between frequency bands, the structure that would normally scatter RF energy is transformed into a cloaked structure that minimizes scattering, allowing radiating elements to be placed closer together without suffering from increased interaction and pattern distortion
3Ease of manufacture
If feed stalks with full ground lines are used, then manufacturing is simplified, but metal content increases causing increased scattering and reduced cloaking performance
Solution Approach 1:
The patent extracts and removes portions of the ground line structure in the feed stalk. Instead of providing continuous full-width ground lines throughout the feed stalk, the invention removes or narrows ground line sections at specific locations (particularly at frequency band interfaces), thereby reducing the metal content that causes scattering while maintaining adequate grounding and RF energy delivery functionality
Solution Approach 2:
The feed stalk structure implements local quality by having ground lines with varying widths or presence at different sections. Certain sections have full-width ground lines for adequate grounding, while other sections (particularly at band boundaries) have narrowed or removed ground lines to minimize scattering, creating a spatially varying structure optimized for both manufacturing and performance
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 modified feed stalks in cross-dipole radiating elements improve cloaking performance, allowing closer spacing of antenna arrays, reducing width, and maintaining optimal antenna beam characteristics across different frequency bands.
Implementation Method 1
The transmission line segment includes a transmission line signal trace that is short-circuited to a ground conductor of the transmission line segment
Data Source
AI summary
A cross-dipole radiating element includes a feed stalk having a base and a distal end that is positioned forwardly of the base, a first dipole radiator mounted at the distal end of the feed stalk, the first dipole radiator including a first dipole arm and a second dipole arm, and a second dipole radiator mounted at the distal end of the feed stalk, the second dipole radiator including a third dipole arm and a fourth dipole arm. The feed stalk includes a first ground line, a first signal trace that at least partially overlaps the first ground line, and a transmission line segment that extends from the first ground line and/or the first signal trace, and the transmission line segment includes a transmission line signal trace that is short-circuited to a ground conductor of the transmission line segment.