Small Cell Beamforming Antenna with Passive Network
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 8T/8R 5G radios are not well-suited for small cell base stations that provide omnidirectional coverage, as they do not utilize all transmit power efficiently, resulting in reduced effective isotropic radiated power (EIRP) compared to conventional systems.
Innovation Solution
The development of small cell beamforming base station antennas with passive beamforming networks that route RF signals from each radio port to a selected subset of linear arrays, allowing for full power utilization and directional radiation patterns while maintaining 360° coverage in the azimuth plane, using a tubular reflector with angled faces and a Butler Matrix or switching network to direct RF energy effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional omnidirectional antennas are used for small cell base stations, then 360° coverage is achieved, but transmit power is not utilized efficiently resulting in reduced EIRP
Solution Approach 1:
The antenna system dynamically switches between omnidirectional and directional beamforming modes based on operational requirements. The passive beamforming network with switching capability allows the system to adapt its radiation pattern, enabling full power utilization in directional mode while maintaining 360° coverage capability when needed.
Solution Approach 2:
The system changes the beamforming parameters (phase and amplitude distribution) across different operating modes. By adjusting the beamforming weights and switching between different beamforming configurations, the antenna can transition from omnidirectional radiation to focused directional beams, optimizing EIRP for specific sectors while maintaining overall coverage capability.
2Power
If 8T/8R 5G radios are used with conventional small cell antennas, then connectivity is provided, but full transmit power is not utilized due to power distribution across all elements
Solution Approach 1:
The antenna system segments the 8T/8R radio output into different selectable groups of antenna elements. The passive beamforming network divides the antenna array into multiple subsets that can be independently activated, allowing the system to concentrate full transmit power on selected elements for directional beamforming while maintaining the capability to use all elements for omnidirectional coverage.
Solution Approach 2:
A passive beamforming network is introduced as an intermediary between the 8T/8R radio and the antenna elements. This network includes phase shifters, power dividers, and switching mechanisms that enable flexible power distribution and element selection, allowing full power utilization without requiring complex active control circuitry in each antenna element.
3Power
If directional beamforming is implemented to increase EIRP, then power utilization improves, but coverage flexibility is reduced
Solution Approach 1:
The antenna system is designed with multi-functionality to perform both omnidirectional coverage and directional beamforming operations using the same hardware infrastructure. The passive beamforming network with its switching capability enables the system to universally support multiple coverage patterns (omnidirectional, sector, directional) without requiring separate antenna systems, thus maintaining coverage flexibility while achieving high EIRP in directional mode.
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
These antennas support higher EIRP levels and can form various directional patterns such as sector, omnidirectional, heart-shaped, and bi-directional beams, utilizing the full transmit power of 5G radios, enhancing coverage and capacity without the need for multiple antenna designs.
Implementation Method 1
each cell is served by a 'macrocell' base station... provide two-way radio frequency ('RF') communications... antenna beam that is generated by each antenna directed outwardly
Implementation Method 2
passive beamforming network that has first through fourth outputs that are coupled to the respective first through fourth arrays of radiating elements... route RF signals from each radio port to a selected subset of linear arrays
Implementation Method 3
The beamforming radio may form a plurality of RF signals... pass each of these RF signals to a respective output port of the radio... columns of radiating elements work together to form a more focused, higher gain antenna beam
Data Source
AI summary
A small cell base station antenna includes a tubular reflector that has at least first through fourth faces that each face in different directions. The antenna further includes first through fourth arrays of radiating elements that are mounted on the respective first through fourth faces of the tubular reflector. The antenna also includes a passive beamforming network that has first through fourth outputs that are coupled to the respective first through fourth arrays of radiating elements.