Foldable Antenna Loop Coupling for Low-Band Folded Efficiency
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Solution Overview
Problem
Foldable electronic devices experience a significant drop in antenna efficiency due to high-loss materials in the gap between foldable bodies, leading to poor antenna performance in the folded state.
Innovation Solution
Implement a foldable electronic device with a main antenna element and a parasitic antenna element that perform current loop radiation, utilizing magnetic field coupling to excite currents in the same direction on overlapping grounding plates, thereby suppressing reverse transverse currents and enhancing longitudinal current excitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the electronic device is folded to improve portability, then the device becomes more compact and portable, but antenna efficiency drops significantly due to high-loss materials in the gap
Solution Approach 1:
The antenna system is divided into two separate antenna elements located on different foldable bodies, allowing each element to function independently while contributing to overall radiation performance
Solution Approach 2:
The two antenna elements are combined through magnetic field coupling to form a collaborative radiation system, where both elements work together to maintain efficient antenna operation in the folded state
2Device complexity
If conventional antenna designs are used in foldable devices, then device structure remains simple, but antenna performance deteriorates in the folded state due to energy absorption by high-loss materials
Solution Approach 1:
The antenna system changes its operational parameters based on device state: in the folded state, it utilizes magnetic field coupling between the two antenna elements to maintain efficient radiation, while in the unfolded state, conventional single-element operation suffices
Solution Approach 2:
Magnetic field coupling serves as an intermediary mechanism that enables effective energy transfer and coordination between the two antenna elements separated by the high-loss material gap, bypassing the detrimental effects of the gap materials
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 approach increases antenna efficiency in the folded state by reducing energy consumption and enhancing excitation effects, resulting in better antenna performance.
Implementation Method 1
The first radiating branch is configured to perform magnetic field coupling with the second radiating branch, to form current loop radiation on both the first radiating branch and the second radiating branch
Data Source
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AI summary
This application provides a foldable electronic device and an antenna system for same. The antenna system includes a main antenna element and a parasitic antenna element. The main antenna element is an antenna structure having a radiation characteristic of a current loop antenna, and includes a feed point and a first radiating branch disposed on a first body of the electronic device. The parasitic antenna element includes a second radiating branch disposed on a second body of the electronic device. In a folded state, the first radiating branch and the second radiating branch are at least partially overlapped. The first radiating branch is configured to perform magnetic field coupling with the second radiating branch, to form current loop radiation on both the first radiating branch and the second radiating branch, and a current direction in a current loop formed on the first radiating branch is the same as a current direction in a current loop formed on the second radiating branch. In this manner, longitudinal currents in a same direction may be simultaneously excited on a foldable grounding plate of the electronic device, to achieve a purpose of reducing or eliminating energy consumed in the folded state and increasing antenna efficiency, effectively resolving a problem of poor antenna efficiency in a low band of the electronic device in the folded state.