Spherical Feed Beamforming for Reflector Aberration Control
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Solution Overview
Problem
Spherical reflector antennas suffer from spherical aberration due to multiple focal points, leading to signal distortion and interference, which is often mitigated by reducing the aperture size, resulting in decreased resolving power and gain.
Innovation Solution
A spherical reflector antenna system with a main spherical reflecting dish and a spherical feed having a plurality of antenna elements on its surface, where a beamforming module activates groups of antenna elements based on a scanning sequence or phase gradient to minimize aberration, using a 3D antenna array to modify received electromagnetic signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a spherical primary mirror is used in a reflector antenna, then the manufacturing complexity and cost are reduced compared to a parabolic mirror, but spherical aberration occurs due to multiple focal points causing signal interference
Solution Approach 1:
The spherical feed is divided into multiple antenna elements arranged in a 3D array on the spherical surface. Each antenna element can be independently controlled and activated, allowing the system to segment the signal processing function across multiple elements to compensate for spherical aberration while maintaining the simple spherical geometry
Solution Approach 2:
The system dynamically activates different groups of antenna elements based on a scanning sequence or activation pattern. This dynamic switching allows the beamforming module to electronically steer and focus signals while compensating for spherical aberration, transforming the static spherical mirror limitation into a dynamically controllable system
2Reliability
If the aperture size of a spherical reflector is reduced to minimize spherical aberration, then signal interference is decreased, but the resolving power and gain of the antenna system are reduced
Solution Approach 1:
The system changes the operational parameters of the antenna elements through beamforming, adjusting phase and amplitude weights dynamically. This allows the full aperture to be utilized while electronically focusing the signal, achieving high resolving power and gain without physically reducing the aperture size
3Reliability
If a parabolic primary mirror is used in a reflector antenna, then a single focal point is achieved providing minimal interference, but the design complexity and manufacturing cost increase significantly
Solution Approach 1:
The spherical feed with multiple antenna elements acts as an intermediary between the simple spherical mirror and the signal processing function. Instead of requiring a complex parabolic mirror shape, the system uses the programmable spherical feed to achieve focal point control, separating the geometric simplicity from the functional complexity
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 solution effectively reduces spherical aberration, maintaining a large aperture while minimizing interference, thus preserving the resolving power and gain of the antenna system.
Implementation Method 1
spherical mirrors have the inherent ability to redirect parallel and non-parallel signals to a feed area
Implementation Method 2
beamforming one or more groups of antenna elements of the 3D antenna array to modify the received EM signals
Data Source
AI summary
Due to its geometry, spherical reflector antenna is inherently diffractive, leading to spherical aberration. Disclosed are example embodiments of methods and systems to minimize or eliminate spherical aberration in a spherical reflector antenna system. One of the systems includes: a main spherical reflecting dish; and a spherical feed having a plurality of antenna elements disposed on a spherical surface. The plurality of antenna elements can be disposed on a convex surface of the spherical surface of the spherical feed facing the main spherical reflecting dish.