Elliptical Strip Antipodal Vivaldi Antenna for Sub-GHz Miniaturization
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Solution Overview
Problem
Existing antipodal Vivaldi antennas are challenging to miniaturize while maintaining effective operation in the sub-GHz frequency range, and existing methods for size reduction are complex and computationally costly.
Innovation Solution
A single elliptical loaded strip antipodal Vivaldi antenna (SELS-AVA) is designed with elliptical conducting strips on the flares, reducing antenna size without compromising radiation and gain performance, using a metallization process to integrate elliptical flares and conducting strips on a substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional Vivaldi antenna designs are used, then the antenna can operate in sub-GHz frequencies, but the antenna size becomes too large for practical energy harvesting applications
Solution Approach 1:
The patent applies parameter changes by modifying the flare shape from traditional exponential or linear tapers to elliptical arcs. This geometric parameter transformation allows the antenna to achieve the same electrical length and radiation performance in sub-GHz frequencies while occupying a smaller physical area. The elliptical flare parameters (major axis, minor axis, arc length) are optimized to maintain impedance matching and radiation efficiency despite the reduced size.
Solution Approach 2:
The patent utilizes another dimension by implementing an antipodal configuration where elliptical flares are placed on both sides of the substrate, extending in opposite directions from the feed point. This bidirectional dimensionality allows the antenna to achieve longer effective electrical length for sub-GHz operation without proportionally increasing the overall footprint, effectively using the third dimension (substrate thickness and bilateral extension) to solve the size-performance contradiction.
2Reliability
If meta-material unit cells and corrugation techniques are applied to enhance gain, then antenna performance improves, but fabrication complexity increases significantly
Solution Approach 1:
The patent extracts and removes the complex meta-material unit cells and corrugation structures from the antenna design, replacing them with simpler elliptical flare geometries. This extraction eliminates the need for complex multi-layer fabrication processes while maintaining gain enhancement through the optimized elliptical shape, which achieves similar or better performance with standard single-layer printing or etching techniques.
Solution Approach 2:
The patent adopts a simpler, more manufacturable design that can be produced using low-cost, standard fabrication processes such as inkjet printing, screen printing, or conventional PCB etching. This approach replaces expensive and complex meta-material structures with affordable elliptical flare designs that achieve comparable gain performance, making the antenna economically viable for mass deployment in IoT and energy harvesting applications.
3Volume of moving object
If resistance loading and slotting techniques are used for miniaturization, then antenna size reduces, but gain enhancement is limited and fabrication becomes more complex
Solution Approach 1:
The patent achieves miniaturization through parameter changes in the flare geometry itself - using elliptical arcs with optimized curvature, major axis, and minor axis dimensions. This geometric parameter optimization provides inherent size reduction without requiring additional resistive loading materials or slot cuts, avoiding the fabrication complexity associated with those techniques while maintaining compact dimensions suitable for portable applications.
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 SELS-AVA achieves a 19.5% reduction in size to 0.359 λL × 0.312 λL while maintaining effective operation from 0.668 GHz to 1.0 GHz with peak gain of 9.5 dBi in the sub-2 GHz frequency band, using computationally efficient finite-difference time-domain (FDTD) method for simulation.
Implementation Method 1
The SELS-AVA is fabricated using a metallization process
Implementation Method 2
The SELS-AVA is configured to radiate at a lower cut-off frequency of about 0.69 GHz
Data Source
AI summary
A single elliptical loaded strip antipodal Vivaldi antenna (SELS-AVA) is formed on a substrate. The SELS-AVA includes a first elliptical flare and a second elliptical flare. A first microstrip feedline is connected to the first elliptical flare and a second microstrip is connected to the second elliptical flare. A base structure is connected to a second end of the second microstrip feedline. The SELS-AVA includes a first elliptical conducting strip connected to the first elliptical flare and a second elliptical conducting strip connected to the second elliptical flare. The second elliptical conducting strip is a mirror image of the first elliptical conducting strip. The SELS-AVA further includes a feed port having a positive terminal and a negative terminal. The SELS-AVA is configured to radiate at a lower cut-off frequency λL of about 0.69 GHz when an electrical signal is applied to the feed port.