Multi-Band Slot Antenna Layout for Compact Wearable GPS Reception
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wearable computing devices face challenges in achieving efficient radiation performance of slot antennas due to limited dimensions, particularly in supporting multiple frequency bands like GPS, while maintaining a compact form factor.
Innovation Solution
Incorporating a parasitic element, such as an electrocardiogram (ECG) electrode, which is electrically and radio frequency (RF) grounded at multiple locations on the printed circuit board, enhances the radiation efficiency of the slot antenna by inducing electrical currents, thereby improving performance at GPS frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a slot antenna is used in a wearable computing device with limited dimensions, then the device maintains a compact form factor, but the radiation efficiency of the antenna deteriorates
Solution Approach 1:
The parasitic element is nested within the existing device structure, utilizing the conductive housing and printed circuit board as part of the antenna system. The parasitic element is positioned between the conductive housing and the printed circuit board, effectively nesting it within the device's existing volume without increasing the overall form factor, while still improving radiation efficiency
Solution Approach 2:
A parasitic element is introduced as an intermediary component between the slot antenna and the ground plane. This parasitic element mediates the electromagnetic field distribution, improving the radiation efficiency of the slot antenna by at least 2 decibels while maintaining the compact wearable form factor
2Adaptability or versatility
If the antenna is designed to support multiple frequency bands including GPS, then the communication versatility is improved, but the antenna design complexity increases
Solution Approach 1:
The slot antenna design with the parasitic element achieves multi-functionality by supporting multiple frequency bands including GPS (1164-1189 MHz), GLONASS (1575.42-1596.85 MHz), and Galileo (1174.45-1215.25 MHz). The same antenna structure serves multiple communication purposes without requiring separate antenna elements for each frequency band
Solution Approach 2:
The antenna design utilizes parameter changes in the parasitic element's dimensions, position, and grounding configuration to achieve resonance at multiple frequency bands. By adjusting these parameters, the antenna can be tuned to support GPS, GLONASS, and Galileo frequency bands using a single integrated structure
3Loss of energy
If a separate parasitic element is added to improve radiation efficiency, then the antenna performance is improved, but the device complexity and component count increase
Solution Approach 1:
The parasitic element is merged with existing device components rather than being a completely separate addition. The parasitic element utilizes the conductive housing and printed circuit board as part of its structure, and the grounding is achieved through existing ground connections on the PCB, thereby improving radiation efficiency without significantly increasing component count or 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 ECG electrode doubles as a parasitic element, enhancing radiation efficiency of the slot antenna by at least 2 decibels without requiring a separate parasitic element, thus optimizing performance across multiple frequency bands.
Implementation Method 1
The slot antenna induces one or more electrical currents on the parasitic element when the slot antenna operates at the one or more global positioning system frequency bands
Implementation Method 2
the parasitic element is radio frequency grounded to the printed circuit board via one or more bypass capacitors
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A wearable computing device is provided. The wearable computing device includes a printed circuit board and a conductive housing. The wearable computing device further includes a slot antenna defined by a gap between the printed circuit board and the conductive housing. The slot antenna is operable at a plurality of different frequency bands. The plurality of different frequency bands include one or more global position system frequency bands. The wearable computing device includes a parasitic element. The parasitic element is electrically grounded to the printed circuit board at a plurality of different locations.