Semiconductor Device Open Stub Feed Line Phase Reflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-finger transistors in high-frequency power amplifiers face inefficiency due to varying distances of open stub connections to gate fingers, leading to suboptimal phase reflection of higher harmonic waves.
Innovation Solution
The open stubs are connected directly to the feed line, ensuring uniform distances and phases across all gate fingers, allowing for optimal reflection and elimination of higher harmonic waves, while maintaining the input line width and preventing efficiency deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If open stubs are connected to the input line in conventional multi-finger transistors, then higher harmonic wave reflection is achieved, but the distances from connection points to gate fingers vary causing suboptimal phase reflection and reduced efficiency
Solution Approach 1:
The patent segments the higher harmonic processing function by providing separate open stubs for each gate finger rather than a single shared connection. This segmentation allows each gate finger to have its own dedicated open stub connected directly to the feed line, ensuring uniform distance and optimal phase reflection for each finger independently.
Solution Approach 2:
The patent introduces the feed line as an intermediary structure that directly connects each open stub to the power supply. This intermediary approach eliminates the need for complex input line routing and allows straightforward direct connections from each open stub to the feed line, achieving uniform distances and optimal phase reflection.
2Loss of energy
If open stubs are connected directly to the feed line with uniform distances, then optimal phase reflection of higher harmonic waves is achieved across all gate fingers, but structural complexity increases
Solution Approach 1:
The patent merges the open stub connections by having all open stubs connect directly to the same feed line structure. This merging approach simplifies the overall connection architecture compared to individual routed connections for each gate finger, reducing layout complexity while maintaining uniform distances and optimal phase reflection.
Solution Approach 2:
The patent changes the connection parameter from variable distances (in conventional structures) to uniform fixed distances by directly connecting each open stub to the feed line at predetermined positions. This parameter standardization simplifies design and manufacturing while achieving optimal higher harmonic wave reflection phases.
3Area of stationary object
If input line width is reduced to accommodate open stub connections, then space is saved, but voltage of fundamental wave becomes out of phase causing efficiency deterioration
Solution Approach 1:
The patent resolves the space conflict by utilizing the vertical dimension and routing open stubs through different layers. The open stubs are configured to extend in directions intersecting the feed line and connect at appropriate positions, allowing the input line to maintain its optimal width for fundamental wave phase uniformity while accommodating higher harmonic processing structures in the vertical dimension.
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 enhances the efficiency of the transistor by ensuring in-phase reflection of higher harmonic waves across all gate fingers, achieving a higher power added efficiency compared to conventional structures.
Implementation Method 1
open stubs, having a line length which eliminates the target higher harmonic wave, and are connected directly to the feed line... the reflection of the higher harmonic wave is in phase in all the gate fingers, and the higher harmonic wave can be eliminated
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In a semiconductor device (1) including gate fingers (2a to 2h) each having a linear shape extending from a feed line (6), and arranged in areas between drain electrodes (3a to 3e) and source electrodes (4a to 4d), open stubs (8a to 8h) are connected directly to the feed line (6).