Dielectric Filter Through-Hole Coupling Without Parasitic Resonance

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Solution Overview

Problem

Conventional dielectric filters experience parasitic resonance effects and complexity in modeling processing due to the implementation of electric coupling between resonators, which affects low band suppression.

Innovation Solution

A dielectric filter design featuring a through hole between blind vias with an insulating portion that partially surrounds the through hole, allowing a 90-degree phase shift of signal waves, thereby implementing electric coupling without parasitic resonance and reducing modeling complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a coupling cavity R3 is used to implement electric coupling between resonators R1 and R2, then electric coupling is achieved, but parasitic resonance effect occurs and low band suppression is affected

Engineering Contradiction:
Improveelectric couplingVSAvoidparasitic resonance effect
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes the coupling cavity R3 from the filter structure and replaces it with a through-hole coupling mechanism. This extraction eliminates the source of parasitic resonance while maintaining the necessary electric coupling between resonators through the through-hole and adjacent blind vias.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a through-hole as an intermediary structure to enable coupling between resonators. The through-hole, together with adjacent blind vias, creates a capacitive coupling mechanism that achieves the desired electric coupling without the parasitic effects associated with traditional coupling cavities.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a coupling cavity R3 is used to implement electric coupling between resonators R1 and R2, then electric coupling is achieved, but modeling processing complexity increases

Engineering Contradiction:
Improveelectric couplingVSAvoidmodeling processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the complex coupling cavity structure and replaces it with a simpler through-hole mechanism. This simplification reduces the number of components and interfaces that need to be modeled, thereby reducing modeling processing complexity while maintaining coupling functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent divides the coupling function into separate elements: the through-hole and adjacent blind vias. This segmentation allows for simpler individual component modeling compared to a monolithic coupling cavity, reducing overall modeling complexity.

Inventive Principle:
Principle #1Segmentation

3Productivity

If conventional dielectric filter structure is used, then production is achieved, but production quality consistency is difficult to ensure

Engineering Contradiction:
ImproveproductionVSAvoidproduction quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The through-hole serves multiple functions: it enables electric coupling between resonators, provides a reference for positioning, and simplifies the overall structure. This multi-functionality reduces the number of separate components needed, thereby improving production quality consistency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses the through-hole as a standardized feature that can be replicated across different filter designs and production batches. This standardization enables consistent manufacturing processes and quality control, improving production quality consistency.

Inventive Principle:
Principle #26Copying

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 proposed design achieves effective electric coupling without parasitic resonance and maintains low band suppression, simplifying the modeling process and ensuring consistent production quality.

Implementation Method 1

the capacitive-coupling structure comprises a through-hole provided between two adjacent dielectric resonators in a dielectric body

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

Because a dielectric filter is a high-Q ceramic dielectric filter, has advantages of low-insertion loss, high suppression

Methodology Applied
Scientific EffectDielectric resonance: Resonance

Data Source

PatentEP4027450B1Dielectric filter and communication device
Publication Date: 2026.03.25 HUAWEI TECH CO LTD
  • EP4027450B1 patent drawingFigure 1~2
  • EP4027450B1 patent drawingFigure 3~5
  • EP4027450B1 patent drawingFigure 6

AI summary

Embodiments of this application provide a dielectric filter and a communication device. The dielectric filter includes: a dielectric body, a first blind via and a second blind via that are provided in the dielectric body, a through hole located between the first blind via and the second blind via, and an insulating portion, where inner walls of the first blind via, the second blind via, and the through hole each are covered with a metal layer, and an outer surface of the dielectric body is covered with a metal layer; and the insulating portion is implemented by not covering a metal layer on a surface of the dielectric body, and the insulating portion partially surrounds the through hole. By using the dielectric filter in the embodiments of this application, when a signal wave entering the first blind via passes through the through hole, a phase of the signal wave negatively shifts for 90 degrees, and the signal wave is transmitted to the second blind via, so that an electric coupling of the dielectric filter is implemented. In such a manner of implementing the electric coupling, because a through hole is provided between the first blind via and the second blind via, modeling processing complexity is reduced. Moreover, such an electric coupling manner does not have a parasitic resonance effect and does not affect low band suppression.