Stepped Impedance Resonator Band-Pass Filter for 5G
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Solution Overview
Problem
Band-pass filters for 5G communication systems in quasi-millimeter and millimeter wave bands face challenges in miniaturization due to the large size of half-wave resonators, which leads to increased insertion loss when using stepped impedance resonators to reduce their length.
Innovation Solution
A band-pass filter design incorporating a plurality of resonators with electromagnetic coupling between adjacent resonators, where specific resonators are configured as stepped impedance resonators closer to the input/output ports to minimize length while maintaining low unloaded Q, thereby reducing insertion loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If stepped impedance resonators are used to reduce resonator length, then miniaturization is achieved, but unloaded Q decreases leading to higher insertion loss
Solution Approach 1:
The patent applies local quality by making only specific resonators (first and second resonators positioned away from the center) as stepped impedance resonators with varying width, while keeping the third resonator (center position) as a constant width resonator. This localized application of impedance variation achieves miniaturization at positions where it benefits coupling characteristics, while preserving high unloaded Q at the center position where it most affects insertion loss.
2Volume of moving object
If all resonators are configured as stepped impedance resonators to achieve miniaturization, then device size is reduced, but insertion loss becomes excessively high
Solution Approach 1:
The patent selectively applies stepped impedance resonator configuration only to specific resonators (first and second resonators) rather than all resonators. The third resonator at the center maintains constant width to preserve high unloaded Q. This selective local application achieves overall miniaturization while preventing excessively high insertion loss that would result from universal application.
Solution Approach 2:
The patent applies stepped impedance resonator design partially rather than excessively to all resonators. By limiting the stepped impedance configuration to only the first and second resonators, the patent achieves sufficient miniaturization effect while avoiding the excessive insertion loss that would result from applying the same design to all resonators including the center third resonator.
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 achieves miniaturization of band-pass filters while preventing an increase in insertion loss, ensuring efficient signal transmission in high-frequency bands.
Implementation Method 1
configured so that electromagnetic coupling is established between every two of the resonators adjacent to each other in circuit configuration
Data Source
AI summary
A band-pass filter includes first to sixth stage resonators. Each resonator includes a resonator conductor portion formed of a conductor line. The resonator conductor portion has a first end and a second end which are opposite ends of the conductor line. The resonator conductor portion of each of the first and sixth stage resonators includes a narrow portion, a first wide portion located between the narrow portion and the first end, and a second wide portion located between the narrow portion and the second end. Each of the first and sixth stage resonators is lower in unloaded Q than the other resonators.