Dielectric Waveguide Filter Trap Resonator Attenuation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Dielectric waveguide filters face challenges in increasing attenuation characteristics without increasing filter length, which is a concern in space-limited applications, and existing coupling methods like direct and cross-coupling are not applicable to filters with only slots and no top surface metallization patterns.

Innovation Solution

A dielectric waveguide filter design incorporating a trap resonator structure with RF signal isolators and coupling windows, utilizing through-holes and conductive material configurations to prevent signal transmission and enable coupling between resonators, allowing for enhanced attenuation without lengthening the filter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional resonators are incorporated to increase attenuation characteristics, then attenuation performance is improved, but filter length increases which is not desirable in space-limited applications

Engineering Contradiction:

Improveattenuation characteristicsVSAvoidfilter length

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

An RF signal isolator is introduced as an intermediary element positioned between adjacent resonators (specifically between the first and second resonators in the second block). This isolator prevents direct signal transmission between these resonators, effectively creating a trap resonator configuration. The isolator acts as a mediator that blocks harmful signal paths while allowing the filter to achieve improved attenuation characteristics without requiring additional resonators that would increase filter length.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If direct and cross-coupling methods are used to increase attenuation, then attenuation characteristics are improved, but these methods require top surface metallization patterns which are not applicable to waveguide filters with only slots

Engineering Contradiction:

Improveattenuation characteristicsVSAvoidapplicability to slot-only waveguide filters

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces the electrical/mechanical coupling method (top surface metallization patterns used in microstrip filters) with an RF signal isolator mechanism. This substituting approach allows the same attenuation enhancement effect to be achieved in waveguide filters that have only slots and no top surface metallization. The RF signal isolator provides the necessary coupling control without requiring the incompatible metallization structures.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If RF signal isolators are used to create trap resonator configuration, then attenuation characteristics increase while maintaining compact filter length, but device complexity increases due to additional components

Engineering Contradiction:

Improveattenuation characteristicsVSAvoidfilter structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The RF signal isolator is integrated into the existing filter structure by positioning it between adjacent resonators in the second block, merging its function with the resonator arrangement. The isolator becomes part of the trap resonator configuration rather than a separate add-on component. This merging approach achieves the desired attenuation enhancement while minimizing the increase in overall device complexity by combining functions within the existing structural framework.

Inventive Principle:

Principle #5Merging (Combining)

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 design effectively increases attenuation characteristics while maintaining a compact filter length, suitable for space-constrained applications, by utilizing RF signal isolators and capacitive coupling windows to create a trap resonator configuration.

Implementation Method 1

an RF signal isolator for preventing the transmission of an RF signal between the first and second resonators

Methodology Applied

Scientific EffectElectromagnetic isolation: Electromagnetic Induction

Implementation Method 2

a first solid block of dielectric material covered with a layer of conductive material and defining a plurality of resonators

Methodology Applied

Scientific EffectWaveguide: Waveguide

Implementation Method 3

defining a plurality of resonators including first and second adjacent resonators

Methodology Applied

Scientific EffectResonance: Resonance

Data Source

PatentUS11437691B2Dielectric waveguide filter with trap resonator

Publication Date: 2022.09.06 CTS CORP

AI summary

A dielectric waveguide filter with a first solid block of dielectric material covered with a layer of conductive material and defining a plurality of resonators. A first RF signal input/output through-hole is defined in a first end resonator of the plurality of resonators of the first block of dielectric material. A second solid block of dielectric material is coupled to the first solid block of dielectric material. The second block of dielectric material is covered with a layer of conductive material and defines a plurality of resonators including first and second adjacent end resonators separated by an RF signal isolator for preventing the transmission of an RF signal between the first and second end resonators. An RF signal coupling window provides a coupling between the first end resonator of the plurality of resonators of the first block of dielectric material and the first end resonator of the second block of dielectric material whereby the first end resonator of the second block of dielectric material defines a trap resonator.