Foldable Device Cable Grounding for RF Resonance Control
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Solution Overview
Problem
The display cable in electronic devices with a hinge structure generates parasitic resonance in the RF Low-Band frequency range, causing noise and degrading the performance of the RF module.
Innovation Solution
A cable structure is implemented with a first cable for transferring display signals and a second cable branched off from the first cable to be grounded to the hinge structure or a heat dissipation member, shortening the ground path and shifting the frequency band of parasitic resonance to an out-of-band range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the display cable length is set to 8-12 cm to accommodate folding/unfolding, then the flexibility and adaptability of the hinge structure is improved, but parasitic resonance occurs in the RF Low-Band frequency range causing noise and degrading RF module performance
Solution Approach 1:
A ground cable is introduced as an intermediary element connected between the display cable and the hinge structure. This ground cable provides a dedicated reference potential path that suppresses parasitic resonance in the display cable, thereby reducing noise without affecting the folding/unfolding flexibility of the hinge structure.
Solution Approach 2:
The electrical parameters of the cable system are modified by adding the ground cable connection. This changes the impedance characteristics and reference potential of the display cable, shifting the parasitic resonance frequency out of the RF Low-Band range and reducing its harmful effects on RF module performance.
2Stability of the object's composition
If the ground path is lengthened to provide stable reference potential, then the electrical stability is improved, but the frequency band of parasitic resonance shifts to the RF Low-Band range causing performance degradation
Solution Approach 1:
The ground cable acts as an intermediary that provides a stable reference potential through connection to the hinge structure. By positioning the ground connection at the hinge rather than extending it through the entire cable length, the design achieves electrical stability while controlling the resonant frequency characteristics.
Solution Approach 2:
The grounding approach transitions from a one-dimensional linear ground path along the cable to a two-dimensional configuration where the ground cable branches off and connects to the hinge structure. This dimensional change allows independent optimization of reference potential stability and resonant frequency characteristics.
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 solution effectively reduces or prevents performance degradation of the RF module by shifting the parasitic resonance frequency out of the supported frequency band, thereby improving communication module performance.
Implementation Method 1
a first cable configured to transfer display signals
Implementation Method 2
a second cable branched off from the first cable to be grounded to the hinge structure
Implementation Method 3
the display cable having a length of 8-12 cm may generate parasitic resonance in an RF Low-Band frequency range
Implementation Method 4
a heat dissipation member disposed on the first housing so as to dissipate heat of the first printed circuit board
Data Source
AI summary
An example electronic device may include a first housing on which a first printed circuit board including a processor is disposed, a second housing on which a second printed circuit board including a display driver for a display is disposed, a hinge structure configured to physically connect the first housing and the second housing such that the first housing and the second housing are foldable/unfoldable, and a cable structure configured to electrically connect the first printed circuit board and the second printed circuit board via the hinge structure. The cable structure may include a first cable configured to transfer display signals and a second cable branched off from the first cable to be grounded to the hinge structure.