Mobile Antenna Stub Layout for Bandwidth Expansion in Ceramic Phones
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Solution Overview
Problem
The performance of antennas in mobile devices is deteriorating due to the reduction in clearance caused by the full-ceramic or glass appearance, which inwardly retracts the metal frame, and existing solutions like parasitic stubs provide limited improvement.
Innovation Solution
The use of a main stub and two parasitic stubs, coupled through electric and magnetic field interactions, to excite multiple resonance modes, enhancing antenna performance and bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the metal frame is inwardly retracted within the screen or battery cover to achieve full-ceramic or glass appearance, then the aesthetic appearance is improved, but the antenna performance deteriorates due to decreased clearance
Solution Approach 1:
The antenna structure is segmented into a main stub and multiple parasitic stubs. The main stub is formed by the inwardly retracted metal frame, while parasitic stubs are added as separate elements coupled to the main stub through gaps. This segmentation allows the antenna to maintain the aesthetic full-ceramic appearance while the parasitic stubs compensate for the performance degradation caused by the retracted metal frame.
Solution Approach 2:
Parasitic stubs serve as intermediary elements between the main stub and the ground. These stubs are coupled to the main stub through gaps (electric field coupling) or adjacent positioning (magnetic field coupling), acting as mediators to enhance the antenna's radiation efficiency and bandwidth without requiring the metal frame to extend outward, thus preserving the aesthetic appearance.
2Reliability
If a single parasitic stub is added to improve antenna performance, then the performance is improved to a limited extent, but the bandwidth and efficiency are insufficient for full-band coverage
Solution Approach 1:
The antenna system is divided into a main stub and multiple parasitic stubs (at least two). Each parasitic stub is configured with specific length and coupling characteristics to resonate at different frequency bands. This segmentation enables the antenna to cover multiple frequency bands (N3, N1, N77) simultaneously, overcoming the limited bandwidth improvement achieved with a single parasitic stub.
Solution Approach 2:
The antenna structure is designed to perform multiple functions: the main stub provides the primary radiation element, while the first and second parasitic stubs are configured to resonate at different frequency bands. This multi-functionality allows a single antenna structure to achieve full-band coverage across N3, N1, and N77 frequencies, making the antenna adaptable to various communication standards.
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
This configuration significantly improves antenna efficiency and bandwidth, achieving full-band coverage of N3, N1, and N77 frequencies, and reduces specific absorption rate (SAR) in mobile devices.
Implementation Method 1
A first parasitic stub and a second parasitic stub are separately coupled to the main stub by electric field coupling
Implementation Method 2
A first parasitic stub and a second parasitic stub are separately coupled to the main stub by magnetic field coupling
Implementation Method 3
the first parasitic stub is configured to excite a resonance in a first mode, and the second parasitic stub is configured to excite a resonance in a second mode
Data Source
Figure 1
Figure 2~4
Figure 5~7
AI summary
This application provides an antenna and a mobile terminal. The antenna may include the following structures: a main stub, a first parasitic stub, and/or a second parasitic stub. The first parasitic stub and the second parasitic stub are respectively arranged on two sides of the main stub. The first parasitic stub and the second parasitic stub are configured to excite resonances to improve main resonance efficiency or expand bandwidth. During specific connection, the first parasitic stub is coupled to the main stub by electric field coupling, and a frequency of the resonance excited by the first parasitic stub is greater than a frequency of a resonance excited by the main stub. The second parasitic stub is coupled to the main stub by electric field and magnetic field coupling, and a frequency of the resonance excited by the second parasitic stub is less than the frequency of the resonance excited by the main stub. In the foregoing technical solution, the first parasitic stub and the second parasitic stub are coupled to the main stub in an electric field coupling manner or an electric field and magnetic field coupling manner, to excite a resonance to improve antenna efficiency, expand bandwidth, and improve antenna performance.