Axisymmetric Reflector Antenna With Close-Coupled Subreflector
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current high-power radio frequency (RF) systems face challenges in efficiently utilizing axisymmetric circular waveguide modes due to the need for mode conversion to interface with typical reflector antennas, resulting in suboptimal pencil beam illumination and performance.
Innovation Solution
The implementation of a reflector antenna system with a concave primary reflector and a coherent-phase sub-reflector, illuminated by a TE01 or TM01 axisymmetric mode feed, allowing the sub-reflector to be positioned close to the feed without significant return loss, and maintaining axisymmetric electromagnetic field distribution for improved beam formation and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If mode conversion is performed to interface axisymmetric circular waveguide mode with typical reflector antenna, then the antenna can be illuminated, but the illumination produces a null in the center of the reflector antenna aperture resulting in poor pencil beam performance
Solution Approach 1:
The patent extracts the sub-reflector from the traditional reflector antenna configuration and positions it very close to the waveguide feed. This extraction allows the sub-reflector to intercept the axisymmetric mode fields before they can create a null in the aperture, and redirect them to properly illuminate the main reflector for pencil beam formation.
Solution Approach 2:
The sub-reflector acts as an intermediary element between the waveguide feed and the main reflector. It receives the axisymmetric mode fields from the feed, transforms their distribution, and illuminates the main reflector in a manner that produces proper pencil beam illumination without the central null problem.
2Volume of moving object
If sub-reflector is positioned close to the feed, then compact design is achieved, but significant return loss occurs with conventional feeds
Solution Approach 1:
The patent changes the modal parameters of the feed by using an axisymmetric circular waveguide mode (TE01 or TM01) instead of conventional modes. This parameter change in the field distribution allows the sub-reflector to be positioned very close to the feed while maintaining low return loss, as the axisymmetric mode fields are naturally suited for this compact configuration.
3Device complexity
If conventional feed is used with typical reflector antenna, then standard configuration is maintained, but the design is not compact and performance is suboptimal
Solution Approach 1:
The patent implements a nested configuration where the sub-reflector is positioned within the focal region of the main reflector, very close to the waveguide feed. This nesting of the sub-reflector within the overall antenna structure enables a compact design while maintaining proper illumination and performance.
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 configuration enables efficient transmission of high-power microwave signals with reduced return loss, allowing for a compact and efficient antenna design suitable for high-power applications, while maintaining azimuthal invariance for beam steering capabilities.
Implementation Method 1
a feed operating with the TE01 or TM01 axisymmetric mode and adapted to appropriately illuminate said coherent-phase subreflector
Implementation Method 2
a coherent-phase sub-reflector disposed one in front of the primary reflector, adapted to reflect a coherently phased axisymmetric electromagnetic wave to appropriately illuminate the aforementioned primary reflector
Implementation Method 3
a concave primary reflector, the concave primary reflector adapted to reflect an axisymmetric aperture electromagnetic field distribution
Data Source
AI summary
A reflector antenna system includes: a concave primary reflector, the concave primary reflector adapted to be illuminated by a sub-reflector and radiate accordingly an axisymmetric beam; a coherent-phase sub-reflector disposed one in front of the primary reflector; and a feed adapted to operate with the TE01 axisymmetric mode and illuminating the said sub-reflector by employment of such. the aperture of the feed disposed to crowd the sub-reflector.