Directional Coupler Inductor Layout for Compact High Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reduction in device size has made it challenging for directional couplers to achieve a desired degree of coupling without increasing their size, as the length of the main and sub-lines is restricted, leading to a shortage in the coupling efficiency.
Innovation Solution
The directional coupler incorporates an inductor connected in series with either the main or sub-line, with specific portions of the wiring lines facing each other such that the direction of signal travel is opposite, enhancing electromagnetic coupling between the main and sub-lines to compensate for the coupling shortage without increasing the coupler's size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the main line and sub-line are made longer to increase the degree of coupling, then the coupling efficiency is improved, but the device size increases
Solution Approach 1:
The patent introduces an inductor connected in series with either the main line or sub-line to change the electrical parameters of the circuit. By adding this reactive component, the coupling efficiency is improved without requiring longer transmission lines, thus maintaining a compact device size while achieving the desired degree of coupling
Solution Approach 2:
The inductor serves as an intermediary element that mediates between the main line and sub-line. It provides an additional path for electromagnetic coupling and allows adjustment of the coupling degree through parameter optimization, enabling high coupling efficiency in a compact structure without directly extending the line lengths
2Volume of moving object
If the device size is reduced to meet miniaturization requirements, then the compactness is improved, but the degree of coupling decreases
Solution Approach 1:
By introducing the inductor and adjusting its inductance value, the electrical characteristics of the directional coupler are modified. This parameter change enables the system to achieve high coupling efficiency in a shorter physical structure, effectively decoupling the relationship between device size and coupling degree
Solution Approach 2:
The patent transitions from relying solely on the spatial dimension (line length) to achieve coupling to utilizing the electrical parameter dimension (inductance). By adding the inductor, the system gains an additional degree of freedom to control coupling efficiency, allowing compact designs to achieve the same coupling performance as larger structures
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 increases the effective degree of coupling and maintains or improves isolation characteristics across the frequency range, effectively addressing the coupling shortage without enlarging the directional coupler.
Implementation Method 1
A first portion of a first wiring line forming the inductor and a second portion of a second wiring line forming the other line among the main line and the sub-line are electromagnetically coupled with each other
Implementation Method 2
a sub-line through which a sub-signal corresponding to the main signal flows by electromagnetic coupling with the main line
Data Source
AI summary
A directional coupler includes: a main line (11) through which a main signal (31) flows; a sub-line (12) through which a sub-signal (32) corresponding to the main signal (31) flows by electromagnetic coupling with the main line (11); and an inductor (13) that is connected in series with one line among the main line (11) and the sub-line (12) and through which one signal among the main signal (31) and the sub-signal (32) flows. A first portion (41) of a first wiring line (21) forming the inductor (13) and a second portion (42) of a second wiring line (22) forming the other line among the main line (11) and the sub-line (12) are electromagnetically coupled with each other.