Pentagonal RF Cover for Offset Antenna Sidelobe Suppression
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Solution Overview
Problem
Parabolic offset antennas experience reduced gain and increased sidelobe levels due to RF devices acting as scatterers, which complicates the design of sidelobe suppression and antenna gain optimization, especially when RF devices are not installed as intended due to external environmental factors.
Innovation Solution
A pentagonal-shaped cover is placed above the RF device, scattering rays and suppressing sidelobes of the elevation angle gain pattern, regardless of the RF device's position inside or outside an avoidance area, thereby improving antenna performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If RF devices are installed at the side of the horn antenna support pedestal, then the antenna can be assembled and operated, but the RF devices act as scatterers that increase the sidelobe level in the radiation pattern
Solution Approach 1:
A cover structure is introduced as an intermediary element between the RF devices and the radiation path. The cover has a specific geometric shape (pentagonal or triangular cross-section) designed to scatter radio waves in controlled directions, preventing them from entering the main radiation beam path while allowing the RF devices to remain in their functional positions for antenna operation
2Ease of operation
If the horn antenna support pedestal structure is added to supply power to the parabolic offset antenna, then the antenna can be fed and operated, but the structure reduces the antenna gain of the parabolic offset antenna
Solution Approach 1:
The cover acts as a mediating structure that allows the support pedestal to fulfill its feeding function while minimizing its harmful impact on antenna gain. The cover's geometry is designed to scatter waves away from the main beam path, reducing the effective blockage and gain loss caused by the presence of the support structure
3Object-generated harmful factors
If RF devices are positioned according to the avoidance area design, then the sidelobe level is minimized, but the antenna cannot adapt to external environmental changes that require repositioning
Solution Approach 1:
The cover converts the harmful scattering effect of RF devices into a beneficial feature. By designing the cover with specific geometric shapes (pentagonal or triangular), the scattered waves are directed in controlled patterns that suppress sidelobes. This allows RF devices to be positioned flexibly without compromising radiation pattern quality, as the cover compensates for position variations
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 pentagonal cover effectively reduces sidelobes in the elevation angle gain pattern, ensuring consistent antenna performance regardless of the RF device's location, and maintains uniform antenna gain across various elevations.
Implementation Method 1
by disposing a cover of a specific shape above an RF device, a sidelobe of an elevation angle gain pattern is suppressed. Specifically, by disposing the cover of a specific shape above the RF device regardless of the inside or the outside of an avoidance area, the sidelobe of the elevation angle gain pattern is improved. For example, the cover has a pentagonal shape, and vertexes of the pentagon are located at the center of the base line of an isosceles triangle to scatter rays.
Data Source
AI summary
The embodiments generally relate to an antenna device that includes a cover having a specific shape to suppress a sidelobe of an elevation angle gain pattern which is caused by a radio-frequency (RF) device regardless of an avoidance area.