Slotted Antenna with Passive Tuning for Compact Wireless Tracking
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Solution Overview
Problem
Wireless communications devices face challenges in miniaturization due to tradeoffs between battery size, antenna efficiency, and signal quality, with existing small antennas often suffering from conductor resistance losses, tuning instability when body-worn, and limited bandwidth, making them impractical for applications like wireless tracking.
Innovation Solution
A communications device with a slotted opening in the electrically conductive antenna layer, incorporating a tuning capacitor and dielectric fill material, and a pressure-sensitive adhesive layer for integration with the body, allowing for adjustable resonance and increased bandwidth through a combination of loop and slot dipole antenna mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If antenna size is reduced for compact device integration, then device portability is improved, but conductor resistance losses increase and antenna efficiency deteriorates
Solution Approach 1:
The patent employs a multi-layer composite structure consisting of conductive antenna layers separated by dielectric layers with different permittivities. This composite approach allows the antenna to maintain efficient current distribution and radiation characteristics at reduced sizes by optimizing the interaction between conductive and dielectric materials, thereby reducing conductor resistance losses while keeping the antenna compact.
Solution Approach 2:
The patent changes the electromagnetic parameters of the antenna system by introducing dielectric layers with specific permittivity values and thicknesses. By adjusting these parameters, the antenna's electrical length and impedance are optimized for compact dimensions, allowing small physical size to achieve adequate radiation efficiency and reduced conductor losses through parameter optimization rather than simply scaling down conventional designs.
2Volume of moving object
If antenna size is reduced for compact device integration, then device portability is improved, but signal quality and gain deteriorate
Solution Approach 1:
The patent transitions from conventional two-dimensional planar antenna designs to a three-dimensional multi-layer stacked configuration. By utilizing the vertical dimension with multiple conductive layers separated by dielectric spacers, the antenna achieves increased effective radiating area and improved gain within a compact footprint, thereby maintaining signal quality while reducing overall device size.
Solution Approach 2:
The multi-layer composite structure with alternating conductive and dielectric layers creates constructive interference patterns and enhances radiation efficiency. This composite design improves signal quality by optimizing the electromagnetic field distribution and increasing the effective aperture of the compact antenna, ensuring reliable communication performance despite reduced physical dimensions.
3Volume of moving object
If conventional small antenna designs are used, then device compactness is improved, but tuning stability when body-worn deteriorates
Solution Approach 1:
The patent designs the antenna system to be insensitive to body proximity effects by creating a multi-layer structure where the combined response of multiple resonant elements provides stable tuning characteristics. The dielectric layers and spaced conductive planes work together to maintain consistent impedance and resonant frequency whether the device is worn on the body or used in free space, achieving universal performance across different operating conditions.
4Volume of moving object
If antenna size is reduced, then device compactness is improved, but bandwidth is limited
Solution Approach 1:
The patent divides the antenna into multiple segmented conductive layers separated by dielectric spacers, with each layer contributing to different aspects of the frequency response. This segmentation allows the compact antenna to achieve broader bandwidth by combining the resonant characteristics of multiple elements, effectively synthesizing a wideband response from individual narrowband components within a reduced physical size.
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 device achieves enhanced efficiency and gain with reduced conductor proximity effect losses, stable tuning, and broad tunable bandwidth, enabling effective operation even at small electrical sizes relative to the wavelength, suitable for compact wireless tracking applications.
Implementation Method 1
The slotted opening (50) provides a combination loop antenna and slot dipole antenna mechanism
Implementation Method 2
The slotted opening (50) provides a combination loop antenna and slot dipole antenna mechanism
Implementation Method 3
The plurality of electrically conductive passive antenna tuning members (43a-43e) may be used to tune the communications device (40) operating frequency
Implementation Method 4
The communications device (40) may further comprise dielectric fill material within the slotted opening
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A communications device (40) includes an electrically conductive antenna layer (41) having a slotted opening (50) therein extending from a medial portion (53) and opening outwardly to a perimeter (54) thereof, the electrically conductive antenna layer (41) including antenna feed points (51a, 51b). The communications device includes a first dielectric layer (42) adjacent the electrically conductive antenna layer (41), an electrically conductive passive antenna tuning member (43a-43e) adjacent the first dielectric layer (42), a second dielectric layer (44) adjacent the electrically conductive passive antenna tuning member (43a-43e), circuitry (48) adjacent the second dielectric layer (44), and electrically conductive vias (55a, 55b) extending through the first (42) and second dielectric layers (44) and coupling the circuitry (48) and the antenna feed points (51a, 51 b). The communications device (40) is integrated and readily manufactured and has reduced packaging with the stacked arrangement. The communications device may operate as a tracking device.