Base Station Antenna Parasitic Element Arrangement
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Solution Overview
Problem
Current base station antennas face challenges in achieving optimal cross-polarization ratio (CPR) and radiation patterns, particularly in the 2.3 to 3.8 GHz frequency band, due to limitations in parasitic element arrangements and spacings, which affect the isolation and efficiency of electromagnetic radiation.
Innovation Solution
The design incorporates a reflector with a radiating element array and a parasitic element array, where parasitic elements are arranged symmetrically and sequentially spaced to overlap projections with the radiating elements, enhancing the cross-polarized radiation and improving the CPR by adjusting the sizes and arrangements of parasitic elements near the cross-polarized radiating elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional parasitic element arrangements are used in base station antennas, then the antenna structure is simpler, but the cross-polarization ratio and radiation pattern performance deteriorate
Solution Approach 1:
The parasitic element array is segmented into multiple pairs (first through third parasitic element pairs) with different spacing configurations. Each pair is positioned at a specific distance from the longitudinal axis, creating distinct functional zones that collectively improve cross-polarization ratio without requiring a single complex configuration
Solution Approach 2:
Different parasitic element pairs are positioned at different distances from the longitudinal axis (first pair closest, second pair intermediate, third pair farthest). This local differentiation in positioning creates varying electromagnetic field interactions at different radial positions, optimizing the overall radiation pattern and cross-polarization characteristics
2Reliability
If parasitic elements are placed closer to the radiating elements, then the coupling effect is stronger, but the isolation between elements deteriorates
Solution Approach 1:
The parasitic elements are arranged in a three-dimensional configuration around the longitudinal axis rather than in a single plane. By distributing elements at different radial distances and angular positions, the design achieves both strong coupling (through proximity in some regions) and good isolation (through spatial separation in other dimensions), resolving the trade-off between coupling strength and element isolation
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 configuration enhances the cross-polarization ratio over sector and improves the radiation pattern, increasing main polarization energy while reducing cross-polarization energy, thereby optimizing antenna performance in the specified frequency band.
Implementation Method 1
a reflector that is configured to provide a ground plane
Implementation Method 2
first parasitic element pairs that respectively extend substantially parallel to a first longitudinal axis of the at least one first cross-polarized radiating element and are respectively coupled to the reflector
Data Source
AI summary
The present invention relates to a base station antenna. The base station antenna comprises: a reflector that is configured to provide a ground plane; a first radiating element array including at least one first cross-polarized radiating element that is arranged on the reflector; and a first parasitic element array including first through third parasitic element pairs, wherein each of the first through third parasitic element pairs includes a pair of parasitic elements that are arranged substantially symmetrically on both sides of the first longitudinal axis, and distances from the first through third parasitic element pairs respectively to the first longitudinal axis increase sequentially, wherein projections of any two of the first parasitic element pair, the second parasitic element pair, the third parasitic element pair, and the at least one first cross-polarized radiating element on the first longitudinal axis at least partly overlap.