Ring-Focus Phased Array Reflector for Wide-Angle Beam Scanning
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Solution Overview
Problem
Conventional direct radiating array (DRA) and phased array fed reflector (PAFR) antenna systems face limitations in wide scan and wide band performance, requiring large apertures, high power consumption, and increased size and cost, while achieving only limited scan volumes.
Innovation Solution
The use of ring-focus optics with an active phased array feed placed concentric with the focal ring of a ring-focus reflector system, which allows for a smaller, lower power, and less complex feed array to achieve a wider scan volume and larger bandwidth, enabling a 360-degree azimuth scan and improved elevation scan volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a direct radiating array is used to achieve wide scan and wide band performance, then the scan volume is improved, but the aperture size, power consumption, weight, and cost increase substantially
Solution Approach 1:
The antenna system is segmented into two functional parts: a relatively small active phased array feed and a large passive reflector. The feed array handles beam steering and scanning functions, while the reflector provides the main gain and aperture illumination, dividing the functional requirements to reduce overall system complexity and feed array size
Solution Approach 2:
The reflector acts as an intermediary element between the small feed array and the far-field radiation pattern. It transforms the limited aperture of the feed array into a large effective aperture, enabling wide scan performance without requiring a proportionally large feed array
2Adaptability or versatility
If the number of radiating elements in the feed array is increased to improve scan performance, then the scan volume increases, but the power consumption and device complexity increase
Solution Approach 1:
The system segments the functional requirements by placing most elements in the passive reflector structure rather than in the active feed array. The feed array uses fewer elements focused on phase control and beam steering, while the reflector elements provide the majority of the radiating aperture
Solution Approach 2:
The patent transitions from a two-dimensional feed array to a three-dimensional configuration by incorporating the reflector surface as an additional dimension of radiation. This allows the system to achieve large aperture effects without proportionally increasing feed array element count
3Volume of stationary object
If a conventional PAFR is used, then the system size is reduced, but the scan volume is limited to less than 5 degrees due to de-focusing loss
Solution Approach 1:
The system dynamically adjusts the phase distribution across the feed array elements as the beam is scanned away from boresight. This dynamic phase compensation counteracts the de-focusing effect, maintaining beam quality and enabling scan volumes of 20-30 degrees while keeping the system compact
Solution Approach 2:
The patent changes the phase parameter of each feed element based on its radial position and the desired scan angle. This parameter adjustment compensates for path length differences and maintains focus across the extended scan volume, overcoming the limitation of conventional PAFR systems
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 approach significantly reduces the prime power and size of the antenna system while maintaining high gain performance, achieving a scan volume of 20-30 degrees and minimizing de-focusing loss, compared to conventional PAFR systems which typically achieve less than 5 degrees.
Implementation Method 1
phased array fed reflectors implemented with ring focus optics
Implementation Method 2
By placing the feed array concentric with the focal ring of a ring-focus reflector system
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3B
AI summary
Systems and methods are provided for wide scan phased array fed reflector systems using ring-focus optics to significantly improve the scan volume of such systems. The subject system includes a reflector having a focal plane and a parabolic curvature configured to receive electromagnetic radiation having a first gain and provide reflected electromagnetic radiation having a second gain greater than the first gain that collimates into a focal ring. The subject system includes a feed array having feed elements positioned about the focal ring, in which each feed element is configured to receive the reflected electromagnetic radiation from the reflector and collimate the reflected electromagnetic radiation into a scanned beam for scanning an annular region. In some aspects, the feed array is centered on the focal ring such that at least one feed element overlaps with the focal ring and remaining feed elements are non-overlapping with the focal ring.