Multilayer Filter Coil Layout for Narrow Passband Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multilayer dielectric filters face the challenge of narrowing the pass frequency band without increasing their size, as reducing the magnetic coupling between resonance electrodes requires increasing the distance between them, thereby enlarging the filter.
Innovation Solution
The filter design incorporates a multilayer body with insulator layers, input and output electrodes, and resonators with coils defined by conductor layers and via hole conductors that penetrate through the insulator layers, allowing for magnetic coupling between coils while maintaining a compact size by utilizing via hole conductors that generate magnetic flux in the z-axis direction and coil conductor layers that loop in the xy plane, reducing strong magnetic coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the distance between resonance electrodes is increased to weaken magnetic coupling and narrow the pass frequency band, then the pass frequency band is narrowed, but the filter size is increased
Solution Approach 1:
The patent introduces via hole conductors that extend in the stacking direction (z-axis) to create magnetic coupling, while coil conductor layers loop in the horizontal plane (xy-plane). This dimensional separation allows the resonance electrodes to be positioned closer together horizontally without increasing strong magnetic coupling, thereby narrowing the pass frequency band without increasing filter size.
Solution Approach 2:
The patent creates different magnetic coupling characteristics in different spatial regions. The via hole conductors provide strong magnetic coupling in the stacking direction where needed, while the coil conductor layers provide magnetic coupling in the horizontal plane. This local differentiation of magnetic coupling properties enables precise control of the pass frequency band without requiring increased electrode spacing.
2Volume of moving object
If the distance between resonance electrodes is decreased to maintain compact size, then the filter size is reduced, but the magnetic coupling is strengthened and the pass frequency band widens
Solution Approach 1:
By utilizing the stacking direction (z-axis) via via hole conductors, the patent creates magnetic coupling pathways that are independent of the horizontal electrode spacing. This allows resonance electrodes to be positioned close together in the horizontal plane (maintaining compact size) while still achieving the desired magnetic coupling strength through the vertical via hole conductors, thus controlling the pass frequency band without being constrained by electrode distance.
3Manufacturing precision
If via hole conductors and coil conductor layers are used to create magnetic coupling, then magnetic coupling strength can be controlled without increasing electrode distance, but the device complexity increases
Solution Approach 1:
The patent combines via hole conductors and coil conductor layers into an integrated resonator structure. The via hole conductors and coil conductor layers work together as a unified magnetic coupling system, where the via hole conductors provide vertical magnetic flux paths and the coil conductor layers provide horizontal magnetic flux paths. This merging of components achieves precise control of magnetic coupling strength while avoiding the complexity of separate adjustment mechanisms.
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 enables the narrowing of the pass frequency band without increasing the filter's size by minimizing strong magnetic coupling between coils, while also allowing for adjustments in magnetic coupling strength and reducing insertion loss.
Implementation Method 1
via hole conductors that generate magnetic flux in the z-axis direction and coil conductor layers that loop in the xy plane, reducing strong magnetic coupling
Data Source
AI summary
A filter includes a multilayer body including a plurality of insulator layers stacked on top of one another. Outer electrodes are provided on surfaces of the multilayer body. A first resonator is connected to a first one of the outer electrodes and includes a first coil. A second resonator is connected to a second one of the outer electrodes and includes a second coil. A third resonator includes a third coil that is magnetically coupled with the first and second coils. The first and second coils are respectively defined by coil conductor layers provided on an insulator layer. The third coil is defined by via hole conductors that penetrate through the insulator layer in a z-axis direction.