Wearable Antenna Design for GPS and Wireless
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wrist-worn devices face challenges in antenna design due to limited space and body effects from close proximity to the user's skin, requiring efficient radiation performance while maintaining compact form factors and user preferences.
Innovation Solution
The design incorporates a coupled loop antenna and a monopole antenna positioned along the periphery of the device's housing, with the coupled loop antenna optimized for GPS signals and the monopole antenna for wireless network communications, both connected to a common ground to minimize interference and enhance radiation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the antenna is positioned close to the ground plane to reduce device size, then the overall device dimensions are reduced, but the radiation efficiency and antenna bandwidth deteriorate
Solution Approach 1:
The antenna system is divided into multiple independent antenna elements (first antenna for GPS, second antenna for wireless networks) positioned at different locations along the periphery of the housing. This segmentation allows each antenna to have adequate clearance from the ground plane while maintaining compact overall device dimensions, resolving the contradiction between small size and radiation efficiency.
Solution Approach 2:
The antennas are positioned along the periphery of the housing in a distributed arrangement rather than concentrating them in one location. This spatial distribution in multiple dimensions allows sufficient distance from the ground plane for optimal radiation performance while keeping the device compact, effectively transitioning from a single-point constraint to a distributed spatial solution.
2Device complexity
If the housing serves as the antenna ground to reduce component size, then the number of components is reduced, but the antenna performance deteriorates due to body effects from close proximity to the user's skin
Solution Approach 1:
Different portions of the housing serve different functions: the housing acts as a ground plane for the antenna system while specific peripheral regions provide antenna mounting locations with adequate clearance from the skin-contacting surfaces. This local differentiation allows the housing to serve multiple functions without compromising antenna performance despite body effects.
Solution Approach 2:
The antenna elements are positioned as intermediary structures between the housing ground plane and the external environment. By placing antennas at specific peripheral locations with adequate clearance, they mediate between the need for a compact housing-as-ground design and the requirement for sufficient clearance to minimize body effects on performance.
3Device complexity
If a single antenna is used to reduce device complexity, then the device complexity is reduced, but the ability to support multiple frequency bands and communication protocols deteriorates
Solution Approach 1:
The antenna system implements multi-functionality by incorporating multiple antenna elements that can operate across different frequency bands. The first antenna supports GPS frequencies while the second antenna supports wireless network frequencies, allowing a single integrated antenna system to perform multiple communication functions simultaneously, resolving the contradiction between simplicity and versatility.
Data Source
AI summary
An antenna is provided for a wearable personal computing device, such as a smartwatch. The antenna integrates with other components of the wearable device, such as a second antenna. For example, the first antenna may be a coupled loop antenna in proximity to a second antenna that may be a monopole antenna, without causing interference between the two antennas. In one example, the first antenna shares a common ground with the second antenna.