Layered Bandpass Filter Resonator Inductance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Layered bandpass filters face challenges in reducing size while maintaining resonator Q, as reducing size can lead to excessive inductive coupling and degradation of resonator performance due to magnetic field interference from conductor layers.
Innovation Solution
A layered bandpass filter configuration with a second resonator having lower inductance and higher capacitance than the first and third resonators, positioned differently within the stacked dielectric layers, and connected via a common conductive path to prevent excessive inductive coupling and maintain resonator performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the size and thickness of the layered bandpass filter are reduced, then the footprint and overall dimensions are decreased, but inductive coupling between adjacent resonators is excessively enhanced
Solution Approach 1:
The patent applies local quality by differentiating the inductance values of resonators based on their positions. Specifically, the second resonator (intermediate resonator) has a different inductance value than the first and third resonators (edge resonators). This local differentiation allows the intermediate resonator to have lower inductance, which reduces excessive inductive coupling with adjacent resonators while maintaining the overall compact size of the filter.
2Length of stationary object
If the distance between conductor layers is reduced to decrease filter thickness, then the overall thickness is decreased, but the magnetic field is hindered by other conductor layers causing degradation in resonator Q
Solution Approach 1:
The patent applies parameter changes by adjusting the inductance values of different resonators to compensate for the degraded magnetic field conditions. When the distance between conductor layers is reduced, the inductance of the intermediate resonator is specifically adjusted to be lower than that of edge resonators. This parameter adjustment compensates for the magnetic field hindrance caused by reduced layer spacing, maintaining resonator Q despite the thinner overall filter structure.
3Length of stationary object
If through holes are shortened to reduce filter thickness, then the overall thickness is decreased, but the inductance of the inductor decreases causing inability to provide desired resonant frequency
Solution Approach 1:
The patent applies parameter changes by differentiating inductance values among resonators based on their positions and the reduced through-hole lengths. The intermediate resonator is designed with lower inductance compared to edge resonators, compensating for the reduced inductance caused by shorter through holes. This allows the filter to maintain desired resonant frequencies despite the reduced thickness and shorter through-hole dimensions.
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
Enables size reduction of the bandpass filter while preventing degradation of resonator Q, allowing for desired resonant frequencies and reduced inductive coupling between resonators.
Implementation Method 1
a first resonator, a second resonator, and a third resonator provided within the layered structure... The first resonator includes a first inductor and a first capacitor. The second resonator includes a second inductor and a second capacitor. The third resonator includes a third inductor and a third capacitor
Implementation Method 2
two adjacent resonators are electromagnetically coupled to each other. The electromagnetic coupling includes inductive coupling and capacitive coupling
Data Source
AI summary
A bandpass filter includes a layered structure including a plurality of stacked dielectric layers, and first to third resonators provided within the layered structure. In terms of circuit configuration, the second resonator is located between the first and third resonators. The first resonator includes a first inductor and a first capacitor. The second resonator includes a second inductor and a second capacitor. The third resonator includes a third inductor and a third capacitor. The second inductor is disposed at a position different from that of each of the first and third inductors in the stacking direction of the dielectric layers. The second inductor is lower in inductance than the first and third inductors. The second capacitor is higher in capacitance than the first and third capacitors.