Dual-Polarized Antenna Beamwidth Control via Virtual Cross-Polarization
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Solution Overview
Problem
Current cellular base station antenna arrays face challenges in minimizing inter-sector interference while maintaining efficient spectral reuse and site tessellation, particularly in achieving optimal azimuth beamwidth and sector power ratio, which can lead to increased antenna size and deployment costs.
Innovation Solution
The use of dual-polarized antenna arrays with 'virtual cross-polarization' techniques and novel unit cell geometries, such as split-vertical and split-horizontal oriented radiating elements, allows for enhanced control over Half Power Beamwidth (HPBW), Front-to-Side Ratio (FSR), and Sector Power Ratio (SPR), enabling optimized cellular network deployment with reduced inter-sector interference and adaptable sector overlap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the 3dB azimuth beamwidth is reduced to improve SPR and minimize inter-sector interference, then spectral efficiency is improved, but the antenna physical size must be increased which pressures site zoning, wind-loading and rentals
Solution Approach 1:
The patent segments the antenna array into multiple independently controllable sub-arrays or element groups, allowing selective activation and beamforming control. This segmentation enables achieving narrow beamwidth for interference reduction without requiring the entire antenna aperture to be physically large, thus resolving the contradiction between beamwidth control and antenna size.
Solution Approach 2:
The patent transitions from controlling beamwidth solely through physical aperture size to using electronic beamforming in the angular domain. By applying phase and amplitude weights to individual elements or sub-arrays, the system can achieve narrow effective beamwidth without increasing the physical antenna footprint, effectively moving the control from spatial dimension to signal processing dimension.
2Adaptability or versatility
If variable azimuth beamwidth antennas are used to improve load balancing and sector overlap control, then network optimization is improved, but the antenna size increases and mechanical/active electronics are required making deployment and maintenance costly
Solution Approach 1:
The patent implements dynamic beamwidth control through electronic means where the beamwidth can be adjusted by changing the excitation patterns of the antenna elements. This dynamic control is achieved without mechanical moving parts by using programmable phase shifters and amplitude controllers, reducing device complexity while maintaining adaptability.
Solution Approach 2:
The patent changes the operational parameters (phase and amplitude) of the antenna elements to achieve variable beamwidth. By modifying these electrical parameters rather than physical dimensions, the system achieves beamwidth adaptability without requiring mechanical adjustments or complex active electronics, thus reducing device complexity.
3Productivity
If aggressive spectral re-use schemes are employed to maximize spectral efficiency, then capacity is improved, but inter-sector and inter-cell interference increases
Solution Approach 1:
The patent applies local quality by creating directionally focused beams that concentrate energy in specific angular sectors. This allows aggressive frequency reuse in different spatial directions while minimizing interference in other directions, enabling high spectral efficiency without proportionally increasing inter-sector interference.
Solution Approach 2:
The patent introduces beamforming as an intermediary mechanism between the transmitted signal and the propagation environment. This beamforming intermediary spatially filters the signals, allowing aggressive spectral reuse by directing energy where needed while suppressing interference in other directions, thus mediating between capacity goals and interference constraints.
Data Source
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AI summary
In one example, the present disclosure provides a dual-polarized antenna array that includes at least one unit cell. The at least one unit cell includes at least one radiating element of a first polarization state and at least two radiating elements of a second polarization state. The second polarization state is orthogonal to the first polarization state. The at least two radiating elements of the second polarization state are displaced on a first side and a second side of the at least one radiating element of the first polarization state.