Multilayer Filter Resonator Layout for Temperature Stability
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Solution Overview
Problem
Existing multilayer bandpass filters experience significant changes in characteristics due to temperature variations, primarily due to the temperature-dependent resonance frequency of dielectric materials, which are not effectively managed by existing technologies.
Innovation Solution
A multilayer filter device is designed with a stack of dielectric layers and integrated conductor resonators, where the resonance frequency of the dielectric material changes linearly within a first temperature range and nonlinearly within a second temperature range, thereby minimizing overall temperature-induced changes in filter characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a multilayer bandpass filter is miniaturized using a stack of dielectric layers, then the filter size is reduced, but the filter characteristics become highly sensitive to temperature changes
Solution Approach 1:
The patent applies parameter changes by selecting dielectric materials with specific temperature coefficients of resonance frequency. The first dielectric layer uses a material with a positive temperature coefficient, while the second dielectric layer uses a material with a negative temperature coefficient. This parameter selection allows the resonance frequency changes of the two layers to counterbalance each other, suppressing overall temperature-induced characteristic changes in the miniaturized filter.
2Reliability
If the temperature coefficient of resonance frequency is suppressed to maintain stable characteristics, then the pass attenuation characteristics remain stable, but other temperature characteristics of the dielectric material are neglected
Solution Approach 1:
The patent applies local quality by assigning different dielectric materials with opposite temperature coefficient signs to different layers (first and second dielectric layers). Each layer has a localized function: the first layer's positive temperature coefficient compensates for the second layer's negative temperature coefficient. This localized differentiation allows comprehensive management of temperature characteristics across the entire filter structure, not just pass attenuation but also resonance frequency stability.
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 approach effectively suppresses changes in filter characteristics due to temperature, ensuring stable performance across a wide temperature range by managing the resonance frequency changes in a controlled manner.
Implementation Method 1
In the dielectric material, the resonance frequency changes linearly with respect to a change in the temperature when the temperature is within a first temperature range, and the resonance frequency changes nonlinearly with respect to a change in the temperature when the temperature is within a second temperature range.
Data Source
AI summary
A filter device includes a stack including a plurality of dielectric layers stacked together, and a resonator configured using a conductor integrated into the stack. Each of the plurality of dielectric layers is formed of a dielectric material, and has a resonance frequency that changes depending on a temperature. In the dielectric material, the resonance frequency changes linearly with respect to a change in the temperature when the temperature is within a first temperature range, and the resonance frequency changes nonlinearly with respect to the change in the temperature when the temperature is within a second temperature range.