Antenna Configuration Eliminates Null-Depths via Polarization Diversity
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Solution Overview
Problem
Existing antenna configurations for base stations in cellular communication systems face challenges in providing omnidirectional radiation patterns without null-depths, especially when combining beams with the same polarization, leading to areas of poor or no coverage, and are non-reversible, increasing system complexity and resource allocation permanently.
Innovation Solution
An antenna arrangement comprising at least three directional antennas with overlapping beams, where two antennas within a cluster have the same polarization and are placed close together, and the third antenna has orthogonal polarization, allowing for omnidirectional coverage by connecting all antennas to the same transmitting line, ensuring no null-depths and adaptable configurations without changing the antenna installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple directional antennas with the same polarization are combined to provide omnidirectional coverage, then the coverage area is improved, but null-depths are created causing areas of poor or no coverage
Solution Approach 1:
The patent applies local quality by assigning different polarization states to different spatial locations (antennas). Specifically, antennas at different positions around the base station are configured with different polarizations (e.g., vertical, horizontal, circular), so that each location contributes differently to the overall radiation pattern. This local differentiation prevents the formation of null-depths while maintaining omnidirectional coverage.
2Productivity
If cell split is implemented to increase load capacity, then the system capacity is improved, but the system complexity and resource allocation are permanently increased
Solution Approach 1:
The patent implements dynamics by enabling reversible configuration of base station antennas. The antenna system can dynamically switch between omnidirectional mode (single cell) and sectorized mode (multiple cells) based on load conditions. This reversibility allows the system to adapt to changing traffic patterns without permanent structural changes, reducing overall system complexity while maintaining high capacity when needed.
3Reliability
If phase shifters are used to move interferometer pattern, then the null-depths are relocated, but the null-depths are not eliminated and the solution is narrowband
Solution Approach 1:
The patent applies parameter changes by modifying the polarization parameter of antennas instead of using phase shifters. By changing the polarization state (vertical, horizontal, circular) rather than the phase, the system eliminates null-depths without introducing bandwidth limitations. This parameter change approach provides a wideband solution that works across the entire operating frequency range.
4Reliability
If orthogonal polarization is used for every other beam, then the radiation pattern is improved, but the solution does not address odd number of beams configuration
Solution Approach 1:
The patent achieves universality by providing a comprehensive solution that works for any number of antennas (odd or even). The method systematically assigns different polarization states to antennas based on their positions, creating a general framework that handles both odd and even numbers of beams. This universal approach eliminates null-depths regardless of the specific antenna configuration.
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 solution enables adaptable antenna configurations for varying load scenarios, providing full 360° omnidirectional coverage without null-depths, reducing operational and capital expenditures by allowing temporary deactivation of base station parts and efficient resource allocation.
Implementation Method 1
at least two directional antennas covering neighbouring angular sectors and with their phase centres within a circle with a radius below two λ are arranged in a first cluster in which all directional antennas have substantially the same polarization... the polarization of the separate directional antenna or the antenna cluster is substantially orthogonal to the polarization of the separate directional antenna or antenna cluster covering a neighbouring angular sector
Implementation Method 2
The main drawback with this solution is that a number of sharp null-depths are created in the 'pseudo-omnidirectional' pattern which will cause areas of poor or no coverage... There is a need to avoid the problem with interferometer pattern causing null-depths that occurs when antenna patterns with the same polarization are combined
Data Source
AI summary
The invention provides an antenna arrangement for a wireless communication system arranged to have at least one transmit mode and at least one receive mode, the arrangement comprising at least three directional antennas in an antenna configuration. Each directional antenna is arranged to have an azimuthal radiation pattern shaped as a beam, each beam covering an angular sector, such that a combined radiation pattern of all beams in a first transmit mode is arranged to provide a full 360° omnidirectional coverage. By combining localization and polarization of the directional antennas an omnidirectional radiation pattern substantially without null-depths in the azimuthal plane can be created when the radiation pattern of the directional antennas are combined.