FSS R-card Antenna Suppresses Ground Plane Interference
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Solution Overview
Problem
Low profile ultra-wideband (UWB) arrays face challenges in achieving wide bandwidth and good scanning range while minimizing size and ground plane interference, with existing technologies struggling to provide efficient impedance matching and radiation efficiency across a broad frequency spectrum.
Innovation Solution
The integration of a frequency selective surface (FSS) resistive card, such as a saw-tooth ring, between the ground plane and tightly coupled dipole antenna elements, which suppresses ground plane interference and enhances impedance matching, allowing for a wideband phased array with scanning capabilities up to 60° in both E- and H-planes, and achieving a bandwidth of at least 50:1 with radiation efficiency of 70% or higher.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a low profile UWB array is used to reduce size, then the antenna profile is reduced, but ground plane interference increases and bandwidth is limited
Solution Approach 1:
A resistive card is introduced as an intermediary component between the ground plane and the antenna elements. This resistive card acts as a mediator that suppresses ground plane interference by absorbing surface waves and reducing unwanted reflections, thereby improving radiation efficiency and bandwidth without compromising the low profile design
Solution Approach 2:
The ground plane is transformed from a conventional solid metal surface to a frequency selective surface (FSS) with specific geometric patterns and resistive loading. This parameter change in the ground plane structure allows it to become frequency-selective, suppressing interference at operating frequencies while maintaining the low profile configuration
2Stability of the object's composition
If conventional ground planes are used to provide reference potential, then electrical stability is improved, but ground plane interference and limited bandwidth occur
Solution Approach 1:
The ground plane is constructed as a composite structure combining FSS patterns with resistive materials. This composite approach integrates the electrical stability function of the ground plane with the interference suppression capabilities of the FSS and resistive card, achieving both stability and reduced ground plane interference simultaneously
Solution Approach 2:
The resistive card serves as an intermediary layer between the conventional ground plane and the antenna elements, allowing the ground plane to maintain its electrical stability function while the resistive card suppresses the harmful interference effects
3Length of stationary object
If tightly coupled dipole elements are used to achieve low profile, then antenna height is reduced, but impedance bandwidth and scanning performance are limited
Solution Approach 1:
The resistive card acts as an intermediary that decouples the antenna elements from ground plane interference, enabling the tightly coupled dipole elements to achieve both low profile and wide impedance bandwidth. The resistive card compensates for the bandwidth limitations that would otherwise result from the low profile configuration
Solution Approach 2:
The resonant frequencies of the FSS ground plane are tuned to coincide with the operating frequencies of the antenna elements. This parameter matching creates a synergistic effect that enhances impedance bandwidth and scanning performance while maintaining the low profile tightly coupled dipole structure
4Loss of energy
If FSS R-card is added to suppress ground plane interference, then radiation efficiency is improved, but device complexity increases
Solution Approach 1:
The FSS pattern and resistive card are merged into a single integrated component rather than separate elements. This merging reduces the number of discrete components and simplifies the overall structure while maintaining the dual functions of interference suppression and efficiency enhancement
Solution Approach 2:
The FSS resistive card performs multiple functions simultaneously: it suppresses ground plane interference, reduces surface wave losses, improves radiation efficiency, and provides mechanical support for the antenna elements. This multi-functionality reduces the need for additional components and simplifies the overall device structure
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 configuration results in an extremely wideband phased array with improved impedance matching and radiation efficiency, enabling scanning up to 60° in both planes with a bandwidth of at least 50:1 and radiation efficiency of 70% or higher, effectively addressing the limitations of existing UWB arrays.
Implementation Method 1
an FSS R-card disposed between the ground plane and the plurality of antenna elements. The FSS R-card can be a ring-style FSS R-card with an air gap therewithin
Implementation Method 2
The FSS R-card can be a saw-tooth ring FSS R-card comprising a grid of square rings... that only attenuates the intended frequencies, thereby increasing total efficiency
Implementation Method 3
The antenna device can further comprise a balun electrically connected to the plurality of antenna elements, and the balun can be a tapered stripline balun comprising an exponentially tapered stripline feed
Implementation Method 4
The plurality of antenna elements can be a TCDA, and each element of the TCDA can have a width equal to λhigh/2
Implementation Method 5
The plurality of antenna elements can comprise capacitive overlaps between adjacent antenna elements
Data Source
AI summary
Antenna devices that include a frequency selective surface (FSS) resistive card (R-card) to suppress ground plane interference are provided. The antenna device can include a tightly coupled dipole array (TCDA), and the FSS R-card can be a saw-tooth ring that only attenuates the intended frequencies. The antenna device can be an extremely wideband phased array with integrated feeding network and spatial scanning down to 60°.