Cellular Antenna Array with Steerable Spotlight Beams
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Solution Overview
Problem
Current cellular antenna array techniques face limitations in providing sufficient wireless coverage with high capacity, especially in densely populated urban areas, due to high sidelobes and non-steerable narrow beams, which lead to energy wastage and interference, and are not suitable for dynamic geographical densities.
Innovation Solution
A cellular antenna array architecture featuring multiple rows of discrete radiators, hybrid couplers, and phase shifters that produce both wide-area coverage beams and steerable spotlight beams from a common aperture, allowing for electronic steering and efficient beam forming with low sidelobes, using an orthogonal dual beam former to integrate regular and spotlight beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a Butler matrix with uniform weight function is used to produce several narrow azimuth beams, then narrow beam-width is achieved, but high sidelobes are produced that waste energy and cause interference
Solution Approach 1:
The patent applies local quality by using non-uniform amplitude weighting (Taylor distribution) across the antenna elements instead of uniform weighting. This creates different amplitude levels at different positions in the array, which suppresses sidelobes while maintaining the desired narrow main beam. The interior elements have different weights than edge elements, optimizing the radiation pattern locally at each position.
Solution Approach 2:
The patent changes the amplitude distribution parameter from uniform to Taylor distribution with specific coefficients. This parameter change transforms the radiation pattern to achieve lower sidelobes while maintaining narrow beam-width. The amplitude weights are calculated using Taylor distribution formulas with controlled sidelobe levels.
2Length of moving object
If an additional antenna with large aperture is added to produce narrow beams, then narrow beam-width is achieved, but real estate on cellular tower is consumed and cost increases
Solution Approach 1:
The patent makes the existing cellular antenna array multi-functional by enabling it to produce both wide coverage beams and narrow spotlight beams through electronic beamforming. The same physical antenna elements serve dual purposes: providing broad sector coverage and forming narrow steerable beams, eliminating the need for additional dedicated antennas for narrow beam coverage.
Solution Approach 2:
The patent introduces dynamic beam steering capability using phase shifters that can electronically redirect beams without physical movement. The beam direction and width can be dynamically adjusted by changing phase and amplitude weights in real-time, allowing the system to adapt between wide coverage and narrow spotlight modes using the same hardware.
3Length of moving object
If fixed geographical density approach is used with additional antenna, then narrow beams are produced, but electronic steering capability is lost
Solution Approach 1:
The patent implements dynamic beam steering through phase shifters connected to each antenna element. The phase and amplitude weights can be electronically adjusted in real-time to steer beams to different directions and change beam widths. This dynamic control enables the system to adapt to varying geographical density requirements and track mobile users without physical antenna movement.
Solution Approach 2:
The patent adds the dimension of electronic control by introducing phase shifters and amplitude weighting networks. This transforms the static antenna radiation pattern into a dynamically controllable system where beam direction, width, and shape can be adjusted independently through electrical parameters, enabling versatile beamforming capabilities.
4Area of stationary object
If standard cellular arrays produce single azimuth beam with wide beam-width, then coverage area is maximized, but capacity in densely populated areas is insufficient
Solution Approach 1:
The patent segments the single wide coverage beam into multiple simultaneous beams with different characteristics. The antenna array can form both wide coverage beams for general service areas and narrow spotlight beams for high-capacity hot spots. This segmentation allows different regions to receive appropriately sized beams, maximizing both overall coverage and localized capacity.
Solution Approach 2:
The patent applies local quality by directing narrow high-capacity spotlight beams to densely populated hot spot areas while maintaining wide coverage beams in other regions. Each geographical area receives a beam tailored to its specific requirements, optimizing capacity where needed while preserving broad coverage elsewhere through spatially selective beamforming.
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 enhances network capacity and reliability by providing high-gain, steerable spotlight beams that can be adapted to various population densities, improving overall aperture efficiency and reducing interference, while maintaining diversity gain and MIMO capability.
Implementation Method 1
Each of the four phase shifters may be used to steer the two spotlights in the azimuth and elevation directions
Implementation Method 2
Multiple discrete radiators at the interior of the rows are fed in pair to a first set of hybrid couplers
Implementation Method 3
A cellular antenna array architecture is disclosed herein, including multiple rows of discrete radiators
Data Source
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AI summary
Cellular array implementations with multiple steerable spotlight beams irradiated from a common aperture are disclosed herein. Such an approach can easily be adapted to suit various geographical population densities and distributions. The array is capable of producing multiple 65-degree cellular coverage beams, which may be used for regular coverage or in MIMO (Multiple Input Multiple Output) mode. The array may also produce multiple steerable beams, or "spotlight" beams. These beams may be relatively narrow and may be steered electronically both in azimuth and elevation directions. By steering the beams in this way, the beams are able to provide cellular services at high-demand "hotspot" regions where high capacity service is required. The spotlight beams may also be used to fill voids or deficiencies caused by regular coverage beams.