Microstrip Filter Resonator Coupling Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional microstrip line resonators face challenges in achieving high Q values in high-frequency bands due to dominant radiation losses, which hinder the realization of filters with steep skirt properties.
Innovation Solution
The design involves a filter structure with resonators formed of microstrip lines connected in cascade, where inter-resonator couplings are optimized by positioning coupling elements within ±45° ranges from voltage maximum points, reducing radiation losses and enhancing Q values by minimizing unnecessary radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional microstrip line resonators are used in high-frequency bands, then the filter can be implemented, but radiation losses increase and Q values decrease
Solution Approach 1:
The patent applies local quality by positioning coupling elements at specific locations (within ±45° from voltage maximum points) rather than uniformly across the resonator. This localized optimization at critical coupling points reduces radiation losses while maintaining the overall filter performance, directly addressing the contradiction between energy loss and reliability in high-frequency bands.
Solution Approach 2:
The patent changes the parameter of coupling element positioning from conventional locations to optimized positions within ±45° ranges from voltage maximum points. This parameter change in the spatial configuration of coupling elements reduces radiation losses and improves Q values, resolving the contradiction between energy loss and reliability.
2Reliability
If inter-resonator coupling is optimized by positioning coupling elements within ±45° ranges from voltage maximum points, then Q values increase and radiation losses reduce, but filter design complexity increases
Solution Approach 1:
The patent defines a specific parameter range (±45° from voltage maximum points) for coupling element positioning that optimizes Q values while providing clear design guidelines. This parameter specification balances the need for high performance with practical design complexity by establishing explicit positioning criteria rather than requiring complex optimization algorithms.
3Manufacturing precision
If coupling elements are positioned to reduce radiation losses, then frequency selectivity improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent focuses precision requirements on local coupling element positions within ±45° ranges from voltage maximum points rather than requiring uniform precision across the entire filter structure. This localized approach to quality control improves frequency selectivity while concentrating manufacturing precision requirements on critical coupling points only.
Solution Approach 2:
The patent specifies a parameter range (±45°) that provides a tolerance window for coupling element positioning. This parameter definition balances the need for precise frequency selectivity with practical manufacturing capabilities by establishing acceptable positioning ranges rather than requiring absolute precision.
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
This approach effectively reduces radiation losses and achieves high Q values even in high-frequency bands, enabling the creation of filters with improved frequency selectivity and insertion loss properties.
Implementation Method 1
a filter to limit a frequency band for a radio communication system is structured by resonant units connected in cascade. Each resonator provided in the resonant unit includes an inductor and a capacitor
Implementation Method 2
inter-resonator couplings are optimized by positioning coupling elements within ±45° ranges from voltage maximum points, reducing radiation losses and enhancing Q values
Data Source
AI summary
A filter includes a resonant unit which has a plurality of resonators respectively formed of each microstrip line and connected in cascade with one another, and a coupling unit which has at least one inter-resonator coupling of the resonant unit in an area within a range of ±45° (⅛-wavelength) in an electrical length from a voltage maximum point at a intermediate of the microstrip line.