Refractive PAFR Reflector Layout for Wide-Scan Aperture Efficiency
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Solution Overview
Problem
Conventional Phased Array Fed Reflector (PAFR) architectures face challenges with large size, weight, and cost due to the need for numerous feed elements and gimbals, and suffer from low aperture efficiency due to the 'sprinkler' effect in ring-focus systems, leading to inefficiencies and increased power consumption.
Innovation Solution
Incorporating a lens element or refraction element between the feed array and reflector components to redirect or redistribute RF energy, enhancing aperture efficiency from 5-10% to 20-25% and reducing the overall size, weight, and cost by focusing or distributing RF energy more effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a ring-focus PAFR architecture is used to widen the scan field of view, then the field of view is improved, but aperture efficiency deteriorates due to the 'sprinkler' effect causing divergent RF energy scattering
Solution Approach 1:
A refractive element is introduced as an intermediary component between the reflector and feed array to correct the divergent RF energy pattern. This element mediates the interaction between the reflector and feed array by refracting the scattered energy back toward the feed elements, thereby recovering aperture efficiency while preserving the wide field of view capability of the ring-focus architecture
Solution Approach 2:
The refractive element changes the directional parameters of RF energy propagation by refracting divergent rays. By altering the angle and direction of reflected energy through controlled refraction, the system converts the harmful divergent pattern into a more concentrated energy distribution that efficiently illuminates the feed array elements
2Adaptability or versatility
If Direct Radiating Array (DRA) architecture is used to provide wide scan and wide band performance, then performance is improved, but the number of feed elements and aperture size must increase substantially
Solution Approach 1:
The invention merges the advantages of reflector architectures (wide scan capability) with phased array capabilities (electronic beam steering) by using a reduced feed array illuminated by a reflector. The refractive element enables this hybrid approach to work efficiently by ensuring proper energy distribution to the fewer feed elements, achieving wide scan performance without requiring the large number of elements needed in pure DRA systems
Solution Approach 2:
The reflector-phased array hybrid system with refractive element serves multiple functions: it provides wide scan coverage through the reflector geometry, enables electronic beam steering through the phased array feed elements, and achieves efficient energy utilization through the refractive correction. This multi-functional design replaces the need for numerous feed elements in traditional DRA systems
3Adaptability or versatility
If a large number of feed elements are used in DRA to achieve wide scan and wide band performance, then performance is improved, but power consumption, weight, size envelope, and cost increase
Solution Approach 1:
The hybrid reflector-phased array design merges the scanning capability of reflectors with the electronic control of phased arrays, enabling wide scan and wide band performance with a much smaller and lighter feed array. The refractive element ensures efficient energy coupling, allowing the system to achieve the same performance with reduced quantity of feed elements, thereby reducing overall weight
4Adaptability or versatility
If gimbals are added to PAFR for greater angular coverage and scanning, then scan coverage is improved, but weight, size envelope, cost, and reliability deteriorate
Solution Approach 1:
The invention replaces the mechanical gimbal system with a stationary reflector architecture combined with electronic beam steering through the phased array feed elements. The refractive element enables the stationary reflector to achieve wide angular coverage by properly directing energy to the electronically controlled feed array, eliminating moving mechanical parts and thereby improving reliability while maintaining scan coverage
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 refraction elements improve aperture efficiency, allowing for smaller reflector and feed arrays, reducing power requirements, and mitigating the 'sprinkler' effect, resulting in a more efficient and cost-effective antenna system.
Implementation Method 1
a lens element configured to alter a distribution of at least a portion of the radio frequency energy reflected by the reflector surface over a detection area of a feed array
Data Source
AI summary
Provided herein are various enhancements for radio frequency antennas and antenna arrangements. In one example, an apparatus comprises a reflector for radio frequency energy having a reflector surface, and a lens element. The lens element is configured to alter a distribution of at least a portion of the radio frequency energy reflected by the reflector surface over a detection area of a feed array positioned a selected distance from the lens element.