Stacked Transmission Line Ground Segmentation for Impedance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-frequency transmission lines face challenges in adjusting impedance and preventing unwanted coupling and radiation due to shared ground layers, which lead to signal leakage and difficulty in achieving desired characteristic impedance.
Innovation Solution
A transmission line configuration with a stacked insulator and conductor patterns where ground conductor patterns are separated and overlap strategically across insulator layers, reducing coupling and radiation, and allowing for a smaller width and reduced transmission loss by optimizing the distance and width of signal and ground conductor patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the pitch of the interlayer connection conductor is made fine, then unwanted coupling between signal lines is reduced, but the capacitance between the signal line and the interlayer connection conductor becomes larger making it difficult to achieve desired characteristic impedance
Solution Approach 1:
The ground conductor pattern is divided into multiple separate ground patterns on different insulator layers. By segmenting the ground conductors and arranging them to overlap in plan view, the patent reduces unwanted coupling between adjacent signal lines while controlling capacitance to maintain desired characteristic impedance.
Solution Approach 2:
The patent transitions from a two-dimensional arrangement to a three-dimensional stacked structure where ground conductor patterns are positioned on different insulator layers and overlap in plan view. This vertical stacking approach reduces coupling between signal lines without requiring fine pitch in the horizontal plane, thus maintaining characteristic impedance.
2Volume of moving object
If the width of the stacked insulator is made smaller, then the capacitance between the interlayer connection conductor and the signal line becomes larger making it difficult to achieve desired characteristic impedance
Solution Approach 1:
By utilizing the vertical dimension through multiple insulator layers and overlapping ground patterns in plan view, the patent reduces the required width of the stacked insulator while maintaining proper capacitance levels for desired characteristic impedance through the distributed ground pattern arrangement.
3Device complexity
If a shared ground layer is used in the stacking direction, then device complexity is reduced, but coupling through the ground layer occurs leading to signal leakage
Solution Approach 1:
The single shared ground layer is segmented into multiple separate ground conductor patterns positioned on different insulator layers. This segmentation prevents coupling and signal leakage between adjacent transmission lines while maintaining relatively simple device structure through the systematic arrangement of ground patterns.
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 effectively reduces unwanted coupling and radiation, ensures predetermined isolation, and allows for a compact design with matched impedance across transmission line portions, even at closer signal conductor spacings, thereby enhancing the transmission line's performance and reducing unwanted radiation.
Implementation Method 1
unwanted coupling between adjacent signal lines is significantly reduced or prevented by the interlayer connection conductor
Implementation Method 2
the capacitance between the signal line and the interlayer connection conductor becomes larger
Data Source
AI summary
A transmission line includes, in a stacked insulator in which insulator layers are stacked, a first transmission line portion including a first ground conductor pattern, a second ground conductor pattern, and a first signal conductor pattern, and a second transmission line portion including a third ground conductor pattern, a fourth ground conductor pattern, and a second signal conductor pattern. The first signal conductor pattern extends along the second signal conductor pattern. The first ground conductor pattern and the third ground conductor pattern are provided on different insulator layers and at least partially overlap each other in a plan view.