Multilayer Filter Module Layout to Limit Inductor Coupling
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Solution Overview
Problem
The challenge is to maintain desired filter characteristics while reducing the size of a multilayer substrate, as overlapping inductor electrodes can lead to characteristic deterioration and make it difficult to form a small-sized substrate effectively.
Innovation Solution
The design includes first and second inductors with individual winding shapes on a multilayer substrate, where the first inductor is positioned differently from other electrodes and the second inductor has a portion parallel to adjacent electrodes, reducing coupling and magnetic field interference, thereby preventing characteristic deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the multilayer substrate size is reduced, then the area is decreased, but inductor electrodes overlap with other electrodes causing characteristic deterioration
Solution Approach 1:
The patent utilizes the third dimension (vertical stacking of multiple insulator layers) to separate inductor electrodes from other electrodes. Instead of only horizontal placement, the design allows inductor electrodes on one layer to overlap with other electrodes on different layers, effectively using vertical separation to prevent harmful coupling while maintaining compact horizontal footprint.
Solution Approach 2:
The patent implements a nested structure where inductor electrodes are positioned within the vertical stack of insulator layers, allowing them to occupy space that would otherwise be unused. The inductor electrodes on intermediate layers are surrounded by insulator layers above and below, creating a nested configuration that minimizes horizontal area while maintaining electrical isolation.
2Reliability
If inductor electrodes are positioned to avoid overlap, then filter characteristics are maintained, but the substrate area increases
Solution Approach 1:
The patent transitions from two-dimensional horizontal separation to three-dimensional vertical arrangement. By placing inductor electrodes on intermediate insulator layers between signal electrodes and ground electrodes, the design achieves electrical isolation without requiring increased horizontal spacing, thus maintaining compact substrate area.
Solution Approach 2:
The substrate is segmented into multiple insulator layers with electrodes placed on different layers. This segmentation allows the inductor electrodes to be isolated from other electrodes by insulator layers, preventing direct coupling while maintaining close horizontal proximity for space efficiency.
3Adaptability or versatility
If multiple inductors are placed on the substrate, then circuit functionality is improved, but electrode overlap and magnetic field interference increase
Solution Approach 1:
The patent positions inductors at different vertical levels using multiple insulator layers. By placing inductor electrodes on different intermediate layers, the design reduces magnetic field coupling between adjacent inductors while maintaining compact horizontal arrangement, thus supporting multiple inductors without excessive interference.
Solution Approach 2:
Insulator layers serve as intermediaries between inductor electrodes and other electrodes, and between adjacent inductors. These insulator layers provide electrical isolation and reduce magnetic field coupling, enabling multiple inductors to coexist on the substrate with minimized interference.
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 or prevents characteristic deterioration, allowing for improved transmission characteristics and easier realization of required circuit characteristics despite a small substrate size.
Implementation Method 1
a first inductor that is connected between the first input and output terminal and the first filter element, and a second inductor that is connected between an end portion of the first inductor and a ground reference potential
Data Source
AI summary
A filter module includes an antenna connection terminal, filter elements, and inductors. The filter elements are connected to an antenna connection terminal. A first inductor is connected between the antenna connection terminal and the filter elements. A second inductor is connected between a transmission line, which connects the first inductor and the filter elements, and a ground reference potential. The filter elements are on an insulating multilayer substrate. The inductors include electrodes on the multilayer substrate. Inductor electrodes of the first inductor and central cavities of the inductor electrodes are at positions different from other electrodes inside the multilayer substrate.