Dielectric Waveguide Filter Cross-Coupling Attenuation
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Solution Overview
Problem
Dielectric waveguide filters face challenges in increasing attenuation characteristics without increasing filter length, particularly in space-limited applications, and existing coupling methods are not applicable to filters without top surface metallization patterns.
Innovation Solution
A dielectric waveguide filter design incorporating both direct and alternative cross-coupled resonators, utilizing internal and external RF signal transmission paths defined by slots and RF signal bridges within the filter blocks, allowing for increased attenuation without lengthening the filter.
Engineering Contradictions & Design Principles
Engineering 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
Solution Approach 1:
The patent transitions from a traditional linear arrangement of resonators to a two-dimensional planar configuration where resonators are arranged in rows and columns. This dimensional change allows multiple resonators to be packed into a compact footprint, achieving high attenuation characteristics without proportionally increasing the filter length. The direct coupling paths are formed within this planar structure, enabling efficient signal transmission across the resonator array.
Solution Approach 2:
The patent combines direct coupling and cross-coupling mechanisms within a unified filter structure. Multiple resonators are interconnected through both direct adjacent coupling and cross-coupling paths, creating a dense network of coupling mechanisms that enhance attenuation performance within a compact length. This merging of coupling approaches allows the filter to achieve superior attenuation without requiring additional length.
2Reliability
If direct and cross-coupling mechanisms are implemented to increase attenuation, then attenuation characteristics are improved, but device complexity increases due to additional coupling structures
Solution Approach 1:
The dielectric material serves multiple functions simultaneously: it acts as the resonator substrate, provides the coupling medium between resonators, and forms the filter housing structure. This multi-functionality reduces the need for separate coupling structures and simplifies the overall device architecture while maintaining effective direct and cross-coupling mechanisms for enhanced attenuation.
Solution Approach 2:
The patent employs a uniform dielectric material throughout the filter structure, creating homogeneous coupling characteristics between all resonators. This homogeneity simplifies the coupling design by providing consistent electrical properties across the entire resonator array, eliminating the need for complex variable impedance structures while achieving effective direct and cross-coupling for improved attenuation.
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 enhances attenuation characteristics without increasing the filter's physical length, providing improved performance through direct and indirect coupling mechanisms within the existing structural constraints.
Implementation Method 1
a plurality of resonators are spaced longitudinally along the length of a monoblock of dielectric/ceramic material
Implementation Method 2
Dielectric waveguide filter with direct coupling and alternative cross-coupling
Data Source
AI summary
A dielectric waveguide filter comprising a block of dielectric material including a plurality of resonators defined by a plurality of slots defined in the block of dielectric material. The resonators are arranged on the block of dielectric material in one or more rows and columns. First and second RF signal input/output electrodes are defined on the block of dielectric material. A first direct RF signal transmission path for the transmission of an RF signal is defined by the first and second RF signal input/output electrodes and the plurality of resonators. In one embodiment, internal windows define a first direct RF signal transmission means and additional RF signal transmission means define alternate or cross-coupling paths for the transmission of the RF signal from resonators in one column to resonators in another column. In one embodiment, the filter is comprised of two separate blocks of dielectric material which have been coupled together.