Lensed Multi-Beam Antenna Sidelobe Suppression
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Solution Overview
Problem
The increased costs and space requirements associated with dividing cellular communication coverage into a greater number of sectors, as well as issues with beam width stability and cross-polarization levels in existing multi-beam base station antennas, are not adequately addressed by current technologies.
Innovation Solution
The development of a lensed multi-beam base station antenna with a sidelobe suppressor, utilizing RF absorber material and RF chokes to reduce sidelobe energy and improve antenna performance, which includes a housing with a lens, reflectors, and radiating elements, where the RF absorber material covers portions of the reflectors to absorb and redirect RF energy, and the RF chokes are used to further suppress sidelobes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of sectors is increased to increase system capacity, then antenna gain and frequency re-use improve, but antenna width and space requirements increase
Solution Approach 1:
The antenna is divided into multiple independent reflector sections (first reflector with first array, second reflector with second array) that can be independently configured. This segmentation allows each sector to be served by a dedicated reflector-array combination, enabling increased sector count without proportionally increasing overall antenna width, as each segment operates semi-independently within the shared housing and lens structure.
Solution Approach 2:
The single lens structure serves multiple reflector arrays simultaneously, providing multi-functionality. The lens is configured to focus RF energy for multiple sectors through different reflector arrays, allowing one lens to support multiple sectors without requiring a separate lens for each sector, thereby increasing system capacity without proportional increases in antenna dimensions.
2Productivity
If the number of sectors is increased to increase system capacity, then antenna gain improves, but costs and space requirements increase
Solution Approach 1:
Multiple reflector arrays and radiating element arrays are merged within a single housing and shared lens structure. The housing contains all components in an integrated assembly, and the lens serves multiple reflector arrays simultaneously. This merging approach allows multiple sectors to be supported within a single antenna unit, increasing system capacity without requiring multiple separate antenna structures, thereby reducing overall complexity and cost.
Solution Approach 2:
The lens is designed as a universal component that serves multiple reflector arrays for different sectors. This multi-functional lens configuration allows a single lens to provide beamforming for multiple sectors, reducing the need for multiple lenses and associated support structures, thereby increasing system capacity while controlling device complexity and cost.
3Area of stationary object
If wider antennas are used to cover larger areas, then coverage area improves, but wind loading and structural support requirements increase
Solution Approach 1:
The antenna structure is segmented into multiple compact reflector-array units within a single housing. Each reflector array serves a specific sector with its dedicated radiating elements, allowing the antenna to provide wide total coverage area through angular distribution of multiple narrow beams rather than requiring a single wide physical aperture. This segmentation maintains a compact overall footprint, reducing wind loading while achieving extensive coverage through multi-sector configuration.
4Measurement precision
If more radiating elements are spaced wider apart to cover narrow sectors, then sector coverage precision improves, but antenna width and zoning compliance issues increase
Solution Approach 1:
The antenna is segmented into multiple independent reflector-array combinations, each dedicated to a specific sector. Each segment contains radiating elements spaced appropriately for its specific sector coverage, optimizing precision for each sector without requiring all elements to be spaced widely across the entire antenna width. This segmentation allows narrow-sector precision to be achieved in each segment while the overall antenna width remains controlled by the housing dimensions.
Solution Approach 2:
The patent utilizes the dimensional space within the housing by arranging multiple reflector arrays at different angles and positions. Instead of increasing antenna width in the horizontal dimension, the solution distributes sector coverage across multiple dimensions within the compact housing, positioning reflectors and radiating elements in three-dimensional space to achieve precise sector coverage without excessive overall antenna width.
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
The solution effectively reduces sidelobe levels by up to 4 dB, improves cross-polarization interference, and enhances antenna gain, providing more efficient and stable sector coverage while minimizing the need for additional structural support and reducing zoning issues.
Implementation Method 1
RF absorber material that covers a portion of the front surface of the planar section of the first reflector and a portion of the front surface of the planar section of the second reflector. The RF absorber material is configured to absorb first RF energy emitted by the first array of radiating elements that is directed toward the second reflector
Implementation Method 2
at least one lens mounted within the housing
Implementation Method 3
a first reflector; and a second reflector. A first array of radiating elements extending forwardly from a front surface of a planar section of the first reflector
Data Source
AI summary
A lensed multi-beam base station antenna may include a plurality of linear arrays of radiating elements, a plurality of reflectors, a sidelobe suppressor, and a lens. Each array may include a plurality of radiating elements (e.g., two or more radiating elements) that extends forwardly from a planar section of a respective reflector. The sidelobe suppressor may comprise radiofrequency (RF) absorber material that absorbs energy that is emitted by a first of the arrays and that is directed toward a reflector underneath a second of the arrays. The sidelobe suppressor may comprise a RF choke that reduces the RF energy emitted by a first of the arrays that is directed toward a reflector underneath a second of the arrays.