Multilayer Band Pass Filter Bypass for Attenuation Pole Tuning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multilayer band pass filters lack the ability to adjust the frequency of attenuation poles generated outside the pass band, making it difficult to achieve a desired frequency characteristic.
Innovation Solution
A multilayer band pass filter design that includes first and second LC parallel resonators with magnetic coupling and a bypass connecting the inductors of these resonators, allowing for adjustment of the frequency of attenuation poles by altering the capacitance of capacitors that couple the resonators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If inter-input-output capacitor electrodes are provided to generate attenuation poles, then the attenuation characteristic from the pass band toward the low-frequency side and high-frequency side can be made steep, but the frequency of attenuation poles cannot be adjusted to achieve desired frequency characteristics
Solution Approach 1:
The inductor is divided into multiple sections with different inductance values. By selectively connecting different sections through switching elements, the overall inductance can be adjusted, which in turn adjusts the frequency of the attenuation pole while maintaining the steep attenuation characteristic provided by the capacitor electrodes.
Solution Approach 2:
The patent introduces switching elements that enable dynamic reconfiguration of the inductor connections. This allows the inductance value to be changed dynamically, thereby adjusting the attenuation pole frequency to match desired frequency characteristics while preserving the steep attenuation provided by the fixed capacitor electrode configuration.
2Device complexity
If the structure is simplified without the bypass, then the device complexity is reduced, but the ability to adjust attenuation pole frequency is lost
Solution Approach 1:
The bypass structure incorporates switching elements that enable dynamic control of the inductor connection. This adds minimal complexity compared to a fully configurable system while providing the essential capability to adjust attenuation pole frequency. The switching elements allow selective engagement of different inductor sections only when frequency adjustment is needed.
Solution Approach 2:
The bypass is designed with localized switching elements positioned at specific points in the circuit where they can effectively adjust the inductance. This localized approach minimizes the overall complexity increase while achieving the frequency adjustment function at the critical points where it is most needed for controlling attenuation pole 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
Enables the frequency characteristic of the multilayer band pass filter to be made close to a desired frequency characteristic by changing the frequency of attenuation poles, without significantly affecting the pass band.
Implementation Method 1
The third LC parallel resonator is magnetically coupled to the first LC parallel resonator. The third LC parallel resonator is magnetically coupled to the second LC parallel resonator.
Data Source
AI summary
A multilayer band pass filter includes a first LC parallel resonator electrically connected to a first input/output terminal, a second LC parallel resonator electrically connected to a second input/output terminal, and a third LC parallel resonator is magnetically coupled to the first LC parallel resonator. The first LC parallel resonator includes a first inductor. The second LC parallel resonator includes a second inductor. The third LC parallel resonator is magnetically coupled to the second LC parallel resonator. A bypass connects the first inductor and the second inductor to each other.