Dielectric Resonator Coupling Holes for Low-Loss Out-of-Band Suppression

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Solution Overview

Problem

Current dielectric filters face challenges in achieving both low insertion loss and large out-band suppression due to difficulties in implementing negative coupling between resonators, which are either complex to tune or result in fragile structures that fail vibration and drop tests.

Innovation Solution

A resonating structure with negative coupling holes (tuning wells) on opposite surfaces of resonators, adjusted by depth, distance, and defect portions, allowing easy tuning of coupling strength without additional metal parts, enhancing stability and production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If more cascaded resonators are used to achieve large out-band suppression, then out-band suppression is improved, but insertion loss increases and filter size increases

Engineering Contradiction:
Improveout-band suppressionVSAvoidinsertion loss
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent introduces a 'zero point' frequency parameter in the transmission function to achieve out-band suppression without increasing the number of resonators. By carefully designing the coupling between resonators to create this zero point, the filter achieves strong out-band suppression while maintaining low insertion loss with fewer resonators.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses an intermediary coupling mechanism between resonators that enables both positive and negative coupling. This intermediary coupling design allows the system to achieve the desired transmission characteristics with fewer resonators, thereby reducing insertion loss while maintaining out-band suppression performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If negative coupling is achieved by arranging a metal part between adjacent resonators, then negative coupling is achieved, but the implementation becomes complex and difficult to tune

Engineering Contradiction:
Improvenegative coupling capabilityVSAvoidimplementation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the metal part from the coupling mechanism and replaces it with a direct dielectric coupling structure. By removing the metal intermediary, the design achieves negative coupling through the dielectric material itself, significantly simplifying the implementation and making it easier to tune by adjusting resonator positions and orientations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical metal part coupling system with a dielectric-based coupling mechanism. This substitution eliminates the need for complex metal component arrangements and enables simpler tuning through direct adjustment of resonator spacing and orientation in the dielectric medium.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If a blind hole is dug deeply to achieve required negative coupling, then negative coupling is achieved, but the dielectric filter becomes fragile and fails vibration and drop tests

Engineering Contradiction:
Improvenegative coupling capabilityVSAvoidstructural robustness
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent achieves the required negative coupling strength without digging excessively deep blind holes. By optimizing the coupling mechanism through resonator positioning and orientation, the system obtains sufficient negative coupling with shallower holes, thereby maintaining structural integrity and passing vibration and drop tests.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the coupling parameters by adjusting resonator positions, orientations, and spacing rather than relying on deep blind holes. This parameter optimization achieves the necessary negative coupling while keeping the blind holes shallow, ensuring the filter meets robustness requirements for vibration and drop tests.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If conventional methods are used to achieve negative coupling, then negative coupling is achieved, but the position of the zero point cannot be adjusted conveniently

Engineering Contradiction:
Improvenegative coupling capabilityVSAvoidzero point adjustability
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent creates a dynamic and adjustable coupling system where the zero point position can be conveniently tuned. By designing the coupling mechanism to allow easy adjustment of resonator positions and orientations, the system enables flexible control over the zero point location in the frequency spectrum, enhancing adaptability for different filter design requirements.

Inventive Principle:
Principle #15Dynamics

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 easy tuning of negative coupling for improved out-band suppression and reduced insertion loss, ensuring robustness and cost-effectiveness in dielectric filters.

Implementation Method 1

dielectric filters that use materials with a high dielectric constant as transmission media

Methodology Applied
Scientific EffectElectromagnetic resonance: Resonance

Implementation Method 2

materials with a high dielectric constant as transmission media

Methodology Applied
Scientific EffectDielectric property: Dielectric

Implementation Method 3

negative coupling (also known as 'capacitive coupling')

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP3949006B1Resonating structure and dielectric filter having the same
Publication Date: 2026.02.25 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3949006B1 patent drawingFigure 1A~1B
  • EP3949006B1 patent drawingFigure 1C~3A
  • EP3949006B1 patent drawingFigure 3B~3D

AI summary

A resonating structure and a dielectric filter having the same are disclosed. According to an embodiment, the resonating structure comprises a body, at least one set of negative coupling holes, and a conductive material layer. The body is made of a solid dielectric material and comprises at least two resonators. The at least one set of negative coupling holes are formed at a connection between two adjacent resonators. Each set of negative coupling holes comprises a first blind hole and a second blind hole disposed on two opposite surfaces of the body respectively. The first blind hole and the second blind hole are offset from each other in a plane perpendicular to a direction along which the first or second blind hole is dug. The conductive material layer covers surfaces of the body and surfaces of the first blind hole and the second blind hole. A transceiver having the dielectric filter and a base station having the transceiver are also disclosed.