Phased Array Antenna Top-Heavy Amplitude for Rooftop Diffraction Losses
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Solution Overview
Problem
Base station antennas deployed on rooftops, set-back from the edge, experience significant diffraction propagation losses due to the rooftop edge, leading to reduced signal strength and in-building penetration.
Innovation Solution
A phased array antenna system with a 'top-heavy' amplitude distribution, where a substantial proportion of RF power is allocated to the upper antenna elements, reducing the grazing angle and diffraction losses, and utilizing appropriate phase weights for robust upper sidelobe level suppression and user-specific beamforming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If base station antennas are deployed set-back from rooftop edges to minimize appearance, then aesthetic acceptance is improved, but diffraction propagation losses increase significantly
Solution Approach 1:
The patent applies local quality by implementing a non-uniform amplitude distribution across the antenna elements, specifically allocating higher amplitudes to upper elements and lower amplitudes to lower elements. This localized variation in amplitude characteristics compensates for the diffraction losses caused by the set-back deployment position, thereby maintaining signal strength while preserving aesthetic acceptance.
Solution Approach 2:
The patent changes the amplitude parameter distribution across the antenna elements from a conventional uniform or symmetric pattern to a skewed distribution where upper elements have higher amplitudes. This parameter change optimizes the radiation pattern to reduce grazing angles and mitigate diffraction losses, resolving the contradiction between set-back deployment benefits and signal strength maintenance.
2Device complexity
If conventional amplitude distribution is used in set-back rooftop deployment, then device complexity is minimized, but propagation losses increase by up to 3dB
Solution Approach 1:
The patent implements local quality through a skewed amplitude distribution that assigns different amplitude levels to different antenna elements based on their position. Upper elements receive higher amplitudes while lower elements receive lower amplitudes, creating a localized optimization that reduces diffraction losses without requiring complex system-level changes.
Solution Approach 2:
The patent applies asymmetry by using an asymmetric amplitude distribution across the vertically arranged antenna elements. Instead of symmetric or uniform amplitude allocation, the distribution is skewed toward upper elements, which asymmetrically compensates for the diffraction effects caused by set-back deployment from the rooftop edge.
3Loss of energy
If RF power is allocated to upper antenna elements to reduce grazing angle, then diffraction losses are reduced, but conventional amplitude distributions fail to provide adequate upper sidelobe suppression
Solution Approach 1:
The patent applies local quality by implementing a skewed amplitude distribution that concentrates higher amplitudes on upper elements. This localized amplitude enhancement reduces grazing angles and diffraction losses while the specific amplitude ratios are optimized to maintain adequate upper sidelobe suppression, balancing both requirements.
Solution Approach 2:
The patent changes the amplitude parameters of individual antenna elements to create a skewed distribution pattern. This parameter optimization simultaneously achieves two objectives: reducing diffraction losses through higher upper element amplitudes and controlling upper sidelobe levels through carefully selected amplitude ratios, resolving the apparent contradiction between these two performance criteria.
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 approach achieves up to 3dB reduction in propagation losses and improved signal strength at the subscriber terminals, enhancing cellular service coverage and user experience, while minimizing the appearance of antennas and reducing inter-site interference.
Implementation Method 1
experience significant diffraction propagation losses due to the rooftop edge
Data Source
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AI summary
In one example, the present disclosure provides a phased array antenna system with a first array of antenna elements and a first radio frequency beamforming network configured to split the power of a radio frequency signal for transmission into a first plurality of component signals comprising drive signals for the first array of antenna elements, the first radio frequency beamforming network further configured to combine a radio frequency signal for reception by the phased array antenna system from a second plurality of component signals from the first array of antenna elements, where a radio frequency power distribution of the first radio frequency beamforming network is arranged to provide a weighting of the first plurality and the second plurality of component signals processed via antenna elements towards one end of the first array.