Multi-band Ground Plane Antenna for Thin Mobile Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Designing a ground plane antenna that effectively operates in limited space while maintaining thin and light appearance of communication devices, as existing antennas require larger sizes to achieve efficient radiation and cover multiple communication bands.
Innovation Solution
A multi-band ground plane antenna is designed with a first radiation element for low-band operations and a second radiation element for high-band operations, where the second current path is longer than the first, allowing the ground plane to excite surface currents and reduce the size of the antenna element, which is optimized with a matching circuit for impedance matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a conventional ground plane antenna is designed to operate in limited space, then the device can maintain a thin and light appearance, but the antenna cannot effectively generate ground plane mode for radiation
Solution Approach 1:
The antenna is divided into two separate radiation elements: a first radiation element for low-band operations and a second radiation element for high-band operations. This segmentation allows each element to be optimized for its specific frequency band, enabling effective ground plane mode generation in limited space while maintaining multi-band functionality.
Solution Approach 2:
The patent utilizes the ground plane as a three-dimensional radiation structure to compensate for the reduced size of the radiation elements. By exciting surface currents on the ground plane, the antenna achieves effective radiation in the low band without requiring a large planar area, thus resolving the contradiction between limited space and effective ground plane mode generation.
2Area of moving object
If the antenna element size is reduced to fit limited space, then the device can maintain thin and light appearance, but the radiation efficiency decreases
Solution Approach 1:
The patent combines the radiation functions of both low-band and high-band operations into a single integrated antenna element structure. The first and second radiation elements work together with the ground plane to achieve multi-band functionality, maintaining radiation efficiency while minimizing the overall antenna element area.
Solution Approach 2:
The ground plane serves as an intermediary structure that enhances the radiation efficiency of the reduced-size antenna elements. By exciting surface currents on the ground plane, the system achieves effective radiation without requiring large antenna elements, thus resolving the contradiction between small size and high radiation efficiency.
3Device complexity
If a single radiation element is used to cover multiple bands, then the device complexity is reduced, but the antenna cannot effectively operate in both low and high bands with optimal performance
Solution Approach 1:
The antenna is segmented into two distinct radiation elements with different current path lengths, where the first radiation element operates in the low band and the second radiation element operates in the high band. This segmentation enables optimal performance in both frequency bands while maintaining a relatively simple overall structure that can be integrated into the device.
Solution Approach 2:
Each radiation element is designed with specific local characteristics optimized for its designated frequency band. The first radiation element has a current path length optimized for low-band operations, while the second radiation element has a longer current path length optimized for high-band operations, allowing both elements to coexist in a single antenna structure with minimal 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 achieves high radiation efficiency of 90% or more for low-band operations and maintains good performance across multiple bands, significantly reducing the antenna element's size to fit various small mobile communication devices.
Implementation Method 1
the ground plane antenna excites a ground plane mode to cover the first band
Implementation Method 2
If surface currents on the ground plane are effectively excited to generate a ground plane mode
Implementation Method 3
If the antenna element resonates in a low band, the ground plane provides 90% or more radiation efficiency
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A communication device including a ground element and an antenna element is provided. The antenna element is close to the ground element. The antenna element includes a first radiation element and a second radiation element. The first radiation element provides a first current path and operates in a first band. The second radiation element provides a second current path and operates in a second band. The frequencies of the second band are higher than those of the first band, and the length of second current path is greater than that of first current path.