Dual-Function Antenna Feed Structure for Frequency-Selective Reflection
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Solution Overview
Problem
Frequency selective surfaces (FSS) subreflectors in dual feed antennas are costly, cumbersome to implement, and provide less than optimum performance due to signal leakage and manufacturing challenges, necessitating a more efficient and cost-effective solution.
Innovation Solution
A dual-function antenna structure incorporating a substrate with an array of antenna elements that passively or actively define both an antenna feed and a subreflector, utilizing capacitive coupling and controllable switches to manage frequency operation, eliminating the need for a standalone FSS subreflector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standalone FSS subreflector is used, then frequency selectivity is achieved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent combines the FSS subreflector and antenna feed into a single integrated structure where the same antenna elements perform both functions. The array of antenna elements on the substrate simultaneously forms the feed for the main reflector and the subreflector for the Cassegrain configuration, eliminating the need for separate components and reducing manufacturing complexity.
Solution Approach 2:
The antenna elements are designed to serve multiple functions: they act as radiating elements for the feed function at one frequency band while simultaneously forming the subreflector surface at another frequency band. This multi-functionality reduces the overall device complexity and manufacturing burden.
2Reliability
If a standalone FSS subreflector is used, then frequency selectivity is achieved, but cost increases
Solution Approach 1:
The integration of FSS subreflector and antenna feed into a single structure reduces the total number of components that need to be manufactured, assembled, and tested. This consolidation directly reduces manufacturing cost while maintaining the frequency selectivity function.
Solution Approach 2:
By making the antenna elements multi-functional, the patent eliminates the need for separate FSS subreflector components, thereby reducing material costs, manufacturing overhead, and assembly costs while preserving the frequency-selective reflecting capability.
3Reliability
If a standalone FSS subreflector is used, then frequency selectivity is achieved, but signal leakage increases
Solution Approach 1:
The integrated structure ensures better impedance matching and reduces discontinuities between the FSS subreflector and feed elements, minimizing signal leakage. The unified design allows for optimized current distribution across the entire structure, reducing energy loss.
Solution Approach 2:
The patent employs controllable switches to dynamically adjust the electrical characteristics of the antenna elements, optimizing the frequency-selective reflecting properties and minimizing signal leakage in different operating conditions. The switches allow precise control over the electrical parameters to reduce energy loss.
4Reliability
If FSS subreflector is applied to compound curve, then focusing is achieved, but manufacturing challenges arise
Solution Approach 1:
The patent uses controllable switches to dynamically configure the antenna elements, allowing the structure to adapt its electrical properties to achieve proper focusing without requiring complex mechanical shaping. The dynamic control enables focusing performance while maintaining a simpler, more manufacturable physical structure.
Solution Approach 2:
By controlling the electrical parameters of the antenna elements through switches, the patent achieves the necessary phase and amplitude distribution for focusing without requiring the elements to be physically shaped according to complex compound curves, thereby simplifying manufacturing.
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 dual-function antenna structure achieves simultaneous operation as an antenna feed and subreflector across multiple frequency bands with reduced signal leakage and manufacturing complexity, enhancing performance and reducing costs.
Implementation Method 1
adjacent legs of adjacent dipole antenna elements including respective spaced apart end portions having shapes and relative positioning to provide capacitive coupling between the adjacent dipole antenna elements
Implementation Method 2
The FSS subreflector 22 may be referred to as a spatial filter, and is a periodic surface with two-dimensional arrays of elements arranged on a dielectric substrate. Depending on the configuration of the array elements, a radio signal will either pass through the FSS subreflector 22 or be reflected by the FSS subreflector 22.
Data Source
AI summary
An antenna may include an antenna main reflector having a shape defining a focal area, and a dual-function antenna structure at the focal area defining a first antenna feed at a first frequency and an antenna subreflector at a second frequency. The dual-function antenna structure may include a substrate and an array of antenna elements carried thereby. A second antenna feed is adjacent the antenna main reflector and operable at the second frequency to cooperate with the antenna subreflector and antenna main reflector.