Base Station Antenna Array Layout for Reduced Pattern Distortion
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Solution Overview
Problem
Base station antennas with closely spaced linear arrays face increased mutual coupling and spatial phase differences due to staggered arrangements, leading to performance degradation and distortion of the radiation pattern, especially when adjusting the elevation angle.
Innovation Solution
Optimized distribution and alignment of radiating elements, including staggered high-band and non-staggered low-band arrays, with phase shifters to align equivalent phase centers and reduce spatial phase differences, thereby improving RF performance and reducing design complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If linear arrays of radiating elements are closely spaced together to enable wide azimuth scanning, then azimuth scanning capability is improved, but mutual coupling between adjacent linear arrays increases degrading co-polarization performance
Solution Approach 1:
The patent introduces a vertical dimension to the array configuration by implementing staggered linear arrays where adjacent arrays are offset vertically by a predetermined distance. This vertical staggering increases the separation between radiating elements in adjacent linear arrays, reducing mutual coupling and improving co-polarization performance while maintaining close horizontal spacing for wide azimuth scanning capability.
2Reliability
If adjacent linear arrays are vertically staggered to reduce mutual coupling, then port-to-port isolation is improved, but spatial phase difference between arrays increases distorting the radiation pattern
Solution Approach 1:
The patent carefully controls the vertical staggering distance between adjacent linear arrays to be a predetermined distance that optimizes the balance between reducing mutual coupling and minimizing spatial phase differences. This parameter optimization ensures that the radiation pattern distortion is kept within acceptable limits while achieving improved port-to-port isolation.
3Adaptability or versatility
If electro-mechanical phase shifters are used to adjust elevation angle for each linear array, then elevation beam steering is improved, but design complexity and cost increase
Solution Approach 1:
The patent implements a common phase shifter configuration where phase shifters are shared across multiple linear arrays rather than dedicating separate phase shifters to each array. This multi-functional approach enables elevation beam steering capability while significantly reducing the overall number of phase shifters required, thereby lowering design complexity and system cost.
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
Maintains the advantages of staggered arrangements while minimizing phase center offsets, enhancing RF performance and reducing distortion, thus improving the overall performance of the base station antenna.
Implementation Method 1
phase shifters to align equivalent phase centers and reduce spatial phase differences
Data Source
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AI summary
The present invention relates to a base station antenna, comprising: a plurality of first radiating elements that are arranged as a first vertically-extending array; a plurality of second radiating elements that are arranged as a second vertically-extending array, where the second radiating elements are staggered in the vertical direction with respect to the first radiating elements; wherein phase centers in an azimuth plane for first sub-arrays of the first radiating elements are substantially the same as phase centers in the azimuth plane for respective third sub-arrays of the second radiating elements, and wherein the first sub-arrays each have a first number of first radiating elements and the third sub-arrays each have a second number of second radiating elements, the first number being different than the second number. This can effectively improve the pattern of the base station antenna.