Modular Wideband Antenna Element Balun Elimination
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Solution Overview
Problem
Current wideband phased array antennas, such as Vivaldi and Bunny Ear elements, require baluns for operation, which increase complexity, cost, and size, and lack modularity and low profile characteristics simultaneously with wideband performance.
Innovation Solution
A modular, low-profile, wideband antenna element design featuring vertically flared fins with metallic strips connecting to the ground plane, eliminating the need for a balun and achieving wideband performance through capacitive coupling and impedance transformation without additional impedance matching networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Vivaldi or Bunny Ear elements are used to achieve wideband performance, then bandwidth is improved, but device complexity increases due to required baluns and impedance matching networks
Solution Approach 1:
The patent extracts and eliminates the balun and impedance matching network from the antenna element structure. The modular element is designed to directly interface with standard 50-ohm RF interfaces without requiring these additional components, thereby reducing device complexity while maintaining wideband performance through the inherent capacitive coupling and impedance transformation of the flared fin structure
Solution Approach 2:
The antenna element structure itself provides the impedance transformation function that previously required separate balun and matching network components. The flared fins with metallic strips create inherent capacitive coupling that transforms impedance from the element to the ground plane, allowing the structure to serve its own impedance matching needs without external components
2Reliability
If Vivaldi elements are used for wideband operation, then bandwidth is improved, but element size increases to several wavelengths at high frequencies
Solution Approach 1:
The patent changes the geometric parameters of the antenna element by using flared fins with exponential or linear tapers instead of the larger Vivaldi slot structure. The metallic strips connecting the fins to the ground plane create capacitive coupling that enables wideband operation with a more compact element size, reducing the physical dimensions while maintaining the required bandwidth performance
3Reliability
If Vivaldi elements are used for wideband scanning arrays, then bandwidth is improved, but modularity is lost due to required electrical connection between neighboring elements
Solution Approach 1:
The patent segments the antenna array into independent modular elements where each element is self-contained with its own ground plane connection. The metallic strips on each element create localized capacitive coupling to the ground plane, eliminating the need for electrical connections between neighboring elements and enabling true modularity while maintaining wideband performance and scan capability
4Length of moving object
If low profile characteristics are desired, then element height is reduced, but achieving wideband performance without balun becomes difficult
Solution Approach 1:
The patent transitions from vertical current distribution to horizontal capacitive coupling by placing metallic strips that extend horizontally from the flared fins to the ground plane. This dimensional change in the current path allows the low-profile element to achieve wideband performance through capacitive coupling in the horizontal plane rather than relying on vertical balun structures
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 design achieves wideband performance, low cost, lightweight, and modular elements with direct interfacing to standard RF interfaces, overcoming the limitations of existing technologies by simplifying fabrication and reducing complexity and cost.
Implementation Method 1
achieving wideband performance through capacitive coupling and impedance transformation
Data Source
AI summary
A modular wideband antenna element for connection to a feed network. There is a ground plane, and first and second flared fins above the ground plane. The fins each define a connection location that is relatively close to the ground plane and tapering to a free end located farther from the ground plane. The connection location of the first fin is electrically coupled to the feed network and the connection location of the second fin is electrically coupled to the ground plane. There are one or more additional first traces electrically connecting the first fin to the ground plane and one or more additional second traces electrically connecting the second fin to the ground plane.