Nested Bowtie Antenna Passive Mixer for Metal Coupling
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Solution Overview
Problem
Miniature passive antennas face limitations when placed on or near metallic objects due to radio interference and coupling issues, which affect their functionality and resonance characteristics, and existing solutions either increase device size, complexity, or add height, making them impractical for foreign object detection applications.
Innovation Solution
The design of nested wideband bowtie antennas with a diode passive mixer, which reduces size, generates mixed signals without power, and maintains bandwidth to minimize coupling effects with metal surfaces, using a combination of frustoconical shapes and a nonlinear device to create a difference-frequency tag that identifies objects through unique radio frequency signatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If miniature passive antennas are placed on or near metallic objects, then the objects can be identified or tracked, but radio interference and coupling issues arise that affect functionality and resonance characteristics
Solution Approach 1:
The patent implements a nested bowtie antenna structure where an inner bowtie antenna is positioned within the structure of an outer bowtie antenna. This nested configuration allows the antenna to maintain its resonance characteristics and functionality when placed near metallic objects, as the nested geometry provides electromagnetic isolation and reduces coupling effects with conductive surfaces.
Solution Approach 2:
The patent transitions from traditional planar antenna designs to a three-dimensional nested bowtie structure. By utilizing vertical stacking and spatial arrangement of the inner and outer antenna elements, the design achieves reduced coupling with metal surfaces through increased dimensional separation, thereby maintaining reliability in challenging electromagnetic environments.
2Object-affected harmful factors
If traditional solutions are implemented to reduce coupling with metal surfaces, then interference is reduced, but device size, complexity, or height increases
Solution Approach 1:
The nested bowtie antenna structure integrates multiple antenna elements within a compact footprint by placing the inner antenna within the geometric boundaries of the outer antenna. This nesting approach reduces overall device complexity compared to using separate isolation structures or multiple stacked layers, while effectively minimizing coupling with metal surfaces through the nested geometry.
Solution Approach 2:
The patent combines the functions of multiple antenna elements into a single integrated nested structure. By merging the inner and outer bowtie antennas into one unified device, the design achieves reduced coupling effects without requiring separate isolation mechanisms or additional structural components, thereby simplifying the overall device architecture.
3Object-affected harmful factors
If bandwidth is increased to minimize coupling effects, then resonance integrity is maintained near metal objects, but antenna size or complexity increases
Solution Approach 1:
The nested bowtie antenna structure maintains resonance integrity near metal objects by utilizing the nested geometry of the inner and outer antenna elements. This configuration preserves the resonant characteristics across a wide bandwidth without requiring additional space, as the nested elements are positioned within each other's geometric boundaries, thereby maintaining a compact footprint while ensuring stable resonance.
Solution Approach 2:
The patent optimizes the geometric parameters of the nested bowtie antenna, including the dimensions, spacing, and orientation of the inner and outer elements, to achieve wide bandwidth operation. By carefully adjusting these parameters, the design maintains resonance integrity across a broad frequency range while minimizing the overall antenna footprint and avoiding increases in device complexity.
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 solution effectively reduces antenna size, eliminates the need for power, and maintains resonance integrity near metal objects, enabling efficient foreign object detection with reduced coupling and increased bandwidth, allowing for multiple band operation and identification of items similar to traditional RFID tags.
Implementation Method 1
a diode assembly on the substrate, and connected to the first ends of the first antenna and to the second ends of the second antenna
Implementation Method 2
The passive difference-frequency tag includes a first antenna on a substrate, the first antenna having a first frequency band, the first antenna having a first shape of a first bowtie
Data Source
AI summary
A passive difference-frequency tag including a first antenna on a substrate, the first antenna having a first frequency band, the first antenna having a first shape of a first bowtie with first rounded end caps and first ends opposed to each other. The passive difference-frequency tag also includes a second antenna on the substrate inside the first antenna. The second antenna has a second frequency band higher than the first antenna frequency band. The second antenna having a second shape of a second bowtie with second rounded end caps and second ends opposed to each other. A combination of the first antenna and the second antenna forms a plurality of multi-band antennas with a shared axis of symmetry. The passive difference-frequency tag also includes a diode assembly on the substrate, and connected to the first ends of the first antenna and to the second ends of the second antenna.