Multilayer Filter Circuit With Coupled Inductors for Sharp Cutoff
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing band-pass filters face challenges in generating an attenuation pole at a frequency range near the cut-off frequency while maintaining a desirable pass characteristic, as LC resonators struggle to implement a sharp change in insertion loss.
Innovation Solution
A multilayered filter device with magnetically coupled inductors and capacitors, comprising a stack of dielectric layers and conductor layers, where inductors are configured to adjoin inside the stack, forming a circuit configuration that includes low-pass and high-pass filters to achieve a sharp pass characteristic near the cut-off frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If LC resonators are used in a band-pass filter, then the filter can be downsized using a stack structure, but the characteristic of changing sharply in attenuation near an attenuation pole becomes difficult to implement
Solution Approach 1:
The filter is divided into multiple resonators (first, second, and third LC resonators) with different functions. The first and second resonators form a magnetically coupled resonant circuit for generating attenuation poles, while the third resonator maintains passband characteristics. This segmentation allows each resonator to be optimized for its specific function, achieving sharp attenuation without compromising overall filter performance.
Solution Approach 2:
Different regions of the filter structure are assigned different properties. The first and second inductors are configured with specific geometries (through-hole lines and conductor layers) to achieve magnetic coupling and generate attenuation poles at specific frequencies. The third inductor is designed to maintain passband characteristics. This local differentiation enables the filter to have sharp attenuation characteristics at cut-off frequencies while maintaining desirable passband performance.
2Manufacturing precision
If attenuation poles are generated near cut-off frequency, then sharp change in insertion loss is achieved, but it becomes difficult to maintain desirable pass characteristic
Solution Approach 1:
The filter is segmented into functionally distinct resonators: the first and second LC resonators are dedicated to generating attenuation poles near cut-off frequencies through magnetic coupling, while the third LC resonator is dedicated to maintaining passband characteristics. This functional segmentation allows independent optimization of attenuation and passband performance without mutual interference.
Solution Approach 2:
The third LC resonator acts as an intermediary element that bridges the attenuation pole generation mechanism and the passband maintenance requirement. By positioning this resonator between the first and second resonators in the circuit configuration, it mediates the interaction between the magnetically coupled resonant circuit and the signal path, ensuring that attenuation poles are generated without degrading passband characteristics.
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
The solution enables a multilayered filter device with a sharp pass characteristic near the cut-off frequency, effectively addressing the challenge of attenuation pole generation and maintaining desirable passband characteristics.
Implementation Method 1
The first inductor and the second inductor are configured to be magnetically coupled inside the stack
Data Source
AI summary
A multilayered filter device includes a first port, a second port, a first LC resonator electrically connected to the first port, a second LC resonator electrically connected to the second port, a third LC resonator provided between the first LC resonator and the second LC resonator in a circuit configuration, and a stack. The first LC resonator includes a first inductor. The second LC resonator includes a second inductor. The first inductor and the second inductor are configured to be magnetically coupled inside the stack.