Pivot-Shaft RF Transmission Line for Foldable Impedance Stability
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Solution Overview
Problem
Foldable 5G electronic devices face issues with discontinuous impedance in radio-frequency transmission lines due to bending, which affects signal quality and frequency band operation.
Innovation Solution
The electronic device features a radio-frequency transmission line with band-shaped line segments and coplanar waveguide segments arranged alternately, where one band-shaped line segment is coupled to a pivot shaft to remain stationary, and coplanar waveguide segments are spaced apart from the pivot shaft's metal portion, ensuring continuous impedance and high signal quality after bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the radio-frequency transmission line is arranged as a metal frame around the electronic device, then the antenna function is achieved, but the device cannot be folded
Solution Approach 1:
The radio-frequency transmission line is divided into multiple segments including coplanar waveguide segments and band-shaped line segments that can be flexibly arranged. This segmentation allows the transmission line to adapt to folded device configurations while maintaining electromagnetic signal transmission functionality.
Solution Approach 2:
The transmission line incorporates a band-shaped line segment coupled to the pivot shaft that remains stationary relative to it, while other segments can bend and deform. This dynamic configuration enables the transmission line to accommodate the folding motion of the device without compromising signal integrity.
2Adaptability or versatility
If the transmission line is bent to accommodate folding, then foldability is achieved, but impedance continuity is disrupted
Solution Approach 1:
Different segments of the transmission line have different structural properties: coplanar waveguide segments are designed to bend with the device, while band-shaped line segments coupled to the pivot shaft remain stationary. This local differentiation ensures that bending occurs in controlled locations without disrupting impedance continuity in critical sections.
Solution Approach 2:
The band-shaped line segment acts as an intermediary element that couples to the pivot shaft and remains stationary during folding, while connecting other parts of the transmission line that undergo bending. This intermediary structure mediates between the stationary and moving parts, maintaining impedance continuity throughout the folded configuration.
3Area of stationary object
If coplanar waveguide segments are placed near the pivot shaft metal portion, then space is utilized, but signal quality deteriorates
Solution Approach 1:
The coplanar waveguide segments are intentionally positioned at a distance from the metal portion of the pivot shaft, extracting them from the immediate vicinity of the metal structure. This separation prevents unwanted electromagnetic interactions and signal degradation while still utilizing the available space effectively in the folded configuration.
Data Source
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AI summary
An electronic device (100) includes first and second bodies (21, 22) rotatably connected through a pivot shaft (4) having a metal portion, the first body (21) including a first motherboard (211), the second body (22) including a second motherboard (221); and a radio-frequency transmission line (1) including at least one band-shaped line segment (11) and at least two coplanar waveguide segments (12), the band-shaped line segment (11) being coupled to the coplanar waveguide segments (12). One band-shaped line segment (11) is located between two coplanar waveguide segments (12), the one band-shaped line segment (11) is coupled to the pivot shaft (4) to retain stationary, and the coplanar waveguide segments (12) are spaced apart from the metal portion. The radio-frequency transmission line (1) has a first end coupled to the first motherboard (211), and a second end coupled to the second motherboard (221).