Multiband Antenna With Frequency Selective Surface
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multiband antennas with multiple antenna elements tuned to different frequency bands experience performance deterioration due to mutual interference between metal elements.
Innovation Solution
A multiband antenna configuration that includes a conductive reflection plate and a frequency selective surface with openings, allowing first and second antenna elements to be positioned in proximity while reducing mutual interference through the use of a stacked structure and feeders passing through openings in the frequency selective surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If multiple antenna elements tuned to different frequency bands are disposed in proximity to reduce distances, then the compactness and integration of the multiband antenna is improved, but the performance of each antenna element deteriorates due to mutual interference between metal elements
Solution Approach 1:
A frequency selective surface (FSS) is introduced as an intermediary structure between the first and second antenna elements. The FSS selectively transmits electromagnetic waves in the first frequency band while reflecting those in the second frequency band, thereby reducing mutual interference between the antenna elements tuned to different frequency bands. This allows the antenna elements to be disposed in proximity without significant performance deterioration.
Solution Approach 2:
The patent employs a stacked configuration where the first antenna elements and second antenna elements are arranged in different spatial layers separated by the frequency selective surface. This three-dimensional arrangement allows compact integration while maintaining performance by utilizing the vertical dimension to separate the antenna elements, reducing their mutual interference through strategic spatial positioning.
2Length of moving object
If antenna elements are disposed in proximity to reduce distances, then the device size is reduced, but mutual coupling between adjacent antenna elements increases causing performance deterioration
Solution Approach 1:
The frequency selective surface acts as a mediator that manages electromagnetic wave interactions between closely spaced antenna elements. By transmitting waves in the first frequency band and reflecting waves in the second frequency band, it prevents harmful mutual coupling while allowing the antenna elements to be positioned close together for compact device design.
Solution Approach 2:
The frequency selective surface provides different electromagnetic properties in different frequency ranges - it is transparent to first frequency band waves and reflective to second frequency band waves. This local quality differentiation allows the antenna elements to be disposed in proximity without significant mutual coupling, as each frequency band experiences different interaction characteristics.
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 configuration effectively reduces the distance between antenna elements tuned to different frequency bands, maintaining performance by minimizing interference and allowing for efficient electromagnetic wave transmission and reception across multiple frequency bands.
Implementation Method 1
a frequency selective surface that is disposed so as to at least partially face the conductive reflection plate, that transmits therethrough electromagnetic waves in a first frequency band
Implementation Method 2
that reflects thereon electromagnetic waves in a second frequency band that is a higher frequency band than the first frequency band
Data Source
AI summary
When a plurality of antenna elements tuned to respective different frequency bands are closely disposed, the performance (the band, the radiating pattern, and so on) of each antenna element may deteriorate. In order to solve the problem, a multiband antenna according to the present invention is provided with: a conductive reflection plate; a frequency selective surface that is disposed so as to at least partially face the conductive reflection plate, that transmits therethrough electromagnetic waves in a first frequency band, that reflects thereon electromagnetic waves in a second frequency band that is a higher frequency band than the first frequency band, and that has a plurality of openings; a plurality of first antenna elements that are disposed in a region sandwiched between the conductive reflection plate and the frequency selective surface and that are tuned to a first frequency included in the first frequency band; and a plurality of second antenna elements that are disposed on a surface opposite the surface of the frequency selective surface facing the first antenna elements, that are fed through feeders passing through the openings, and that are tuned to a second frequency included in the second frequency band.