Imaging Array Fed Reflector Antenna Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-beam antenna systems for spacecraft face inefficiencies due to shared radiating elements, requiring multi-carrier operation which leads to amplifier output back-off, reduced efficiency, and increased power and heat generation, or necessitate higher power amplifiers and redundancy, resulting in higher cost and complexity, while being scan limited by reflector offset distortion.
Innovation Solution
A multi-beam antenna system utilizing an imaging array fed reflector with dedicated clusters of radiating elements and power amplifiers for each beam, arranged in a close-packed triangular lattice, eliminating element sharing and employing gallium nitride solid-state power amplifiers to minimize line losses and reduce component complexity, with soft redundancy and Doherty amplifier configurations for improved efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If shared radiating elements are used between multiple beams, then device complexity is reduced, but beam forming efficiency deteriorates and multi-carrier operation is required leading to amplifier output back-off and reduced amplifier efficiency
Solution Approach 1:
The antenna system divides the radiating elements into dedicated clusters, where each cluster is assigned to a specific beam. This segmentation eliminates element sharing between beams, allowing each beam to have its own dedicated radiating elements and power amplifiers, thereby improving beam forming efficiency without significantly increasing overall system complexity
Solution Approach 2:
The patent transitions from a conventional 2D planar array to a 3D volumetric arrangement of radiating elements distributed throughout a reflective volume. This dimensional change enables dedicated element clusters for each beam while maintaining compact overall structure, resolving the complexity-efficiency trade-off
2Adaptability or versatility
If multi-carrier operation is implemented with shared elements, then beam coverage is improved, but amplifier efficiency deteriorates due to output back-off and increased power consumption
Solution Approach 1:
The system segments power amplifiers into dedicated groups for each beam, eliminating the need for multi-carrier operation with shared amplifiers. Each beam has its own power amplifiers operating at full efficiency, dramatically reducing total power consumption while maintaining comprehensive beam coverage
Solution Approach 2:
The patent changes the operational parameters by assigning dedicated power amplifiers to each beam, allowing them to operate at optimal power levels without the output back-off required in shared-element multi-carrier systems. This parameter change directly improves amplifier efficiency and reduces power consumption
3Loss of energy
If dedicated power amplifiers per beam are used, then amplifier efficiency is improved, but device complexity and cost increase
Solution Approach 1:
The patent merges the functions of multiple dedicated amplifiers into integrated amplifier clusters associated with each beam. This consolidation reduces the number of discrete components and interconnections, lowering system complexity while maintaining the efficiency benefits of dedicated amplification for each beam
Solution Approach 2:
The amplifier clusters are designed with universal functionality to handle multiple beams through selective activation. Each amplifier cluster can serve its dedicated beam while potentially supporting adjacent beams, reducing the total number of amplifiers needed and simplifying the overall system architecture
4Reliability
If conventional multi-reflector MBA is used with single feed horn per beam, then beam isolation is improved, but system complexity and cost increase due to higher power amplifiers and redundancy requirements
Solution Approach 1:
The patent replaces the conventional multi-reflector 2D structure with a 3D distributed array of radiating elements throughout a reflective volume. This dimensional transformation achieves superior beam isolation through spatial distribution and phase control, eliminating the need for complex multi-reflector architectures and associated redundancy requirements
Solution Approach 2:
The invention substitutes mechanical/physical separation methods (multiple reflectors) with electromagnetic field control methods (phase and amplitude modulation of distributed elements). This substitution achieves beam isolation through signal processing rather than physical separation, reducing system complexity while improving performance
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
An imaging array fed reflector for a spacecraft is included in a spacecraft payload subsystem. The payload subsystem includes a multi-beam antenna including a reflector, a plurality of amplifiers, and a plurality of radiating feed elements, the feed elements configured as a phased array, illuminating the reflector, operable at a frequency having a characteristic wavelength (λ), and configured to produce, in a far field at the reflector, a set of contiguous abutting beams. The amplifiers are disposed proximate to the plurality of radiating feed elements. Each radiating feed element has a respective coupling with at least one respective amplifier of the plurality of amplifiers. Each radiating feed element, together with the at least one respective amplifier, is disposed in a closely packed triangular lattice such that separation between adjacent radiating feed elements is not greater than 1.5λ.