3D Ring Resonator Filter for Low-Loss Millimeter-Wave Passbands
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing filters struggle to maintain low transmission loss and flatness in millimeter wave frequency bands, especially in limited product areas, affecting the linearity of radio transmitting systems.
Innovation Solution
A 3D filter design with a staggered structure incorporating multiple circuit layers and via structures to achieve low loss and high flatness, utilizing ring resonators and orthogonal feed-in lines to form a composite passband.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If filters are designed to meet requirements in a limited product area, then the area occupied by the filter is reduced, but the transmission loss increases and flatness deteriorates
Solution Approach 1:
The patent transitions from a planar 2D filter design to a 3D filter design by stacking multiple circuit layers (first, second, and third circuit layers) vertically. This dimensional change allows the filter to achieve the required frequency selection functionality while occupying a smaller footprint area on the substrate, thereby resolving the contradiction between reducing filter area and maintaining transmission loss performance.
Solution Approach 2:
The patent employs multiple ring resonators of different sizes (first ring resonator with first ring surrounded area, second ring resonator with second ring surrounded area) that are nested or stacked across different circuit layers. These nested resonator structures enable compact integration while maintaining the electrical characteristics needed for low transmission loss and high flatness in the passband.
2Area of stationary object
If filters are designed to meet requirements in a limited product area, then the area occupied by the filter is reduced, but the flatness deteriorates
Solution Approach 1:
By utilizing multiple circuit layers stacked in the vertical dimension, the patent achieves high flatness characteristics across the passband without increasing the planar footprint. The multi-layer configuration allows for optimized electromagnetic field distribution that maintains signal integrity and flatness while minimizing the area occupied by the filter.
Solution Approach 2:
The patent employs asymmetric design in the ring resonator structures, where the first ring resonator and second ring resonator have different ring surrounded areas and are positioned at different locations on respective circuit layers. This asymmetric configuration enables optimized electromagnetic coupling and field distribution that achieves high flatness characteristics while maintaining a compact form factor.
3Ease of manufacture
If conventional 2D filter structures are used, then the fabrication process is simple, but the filter cannot achieve low loss and high flatness in millimeter wave frequency bands
Solution Approach 1:
The patent extends the conventional 2D filter design into the third dimension by introducing multiple circuit layers stacked vertically. This 3D configuration improves transmission loss characteristics in millimeter wave frequency bands while maintaining compatibility with standard PCB fabrication processes, thus achieving better performance without significantly complicating the manufacturing process.
Solution Approach 2:
The multi-layer circuit board structure serves multiple functions simultaneously: it provides electrical connectivity between different signal paths, creates the necessary electromagnetic resonances for filtering, and maintains mechanical support for the entire filter assembly. This multi-functionality allows the same structural elements to achieve both low transmission loss and ease of manufacture.
4Ease of manufacture
If conventional 2D filter structures are used, then the fabrication process is simple, but the filter cannot achieve high flatness in millimeter wave frequency bands
Solution Approach 1:
The transition to a 3D multi-layer structure enables the filter to achieve high flatness characteristics in the passband by optimizing electromagnetic field distribution across multiple layers. The vertical stacking allows for better control of signal paths and reduced interference, improving flatness while remaining compatible with standard fabrication techniques.
Solution Approach 2:
The asymmetric arrangement of ring resonators across different circuit layers, with different ring surrounded areas and positions, creates optimized electromagnetic coupling that achieves high flatness characteristics. This asymmetric design can be implemented using conventional PCB manufacturing processes, maintaining ease of manufacture while achieving superior electrical performance.
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 3D filter design achieves low loss and high flatness characteristics, enabling smaller form factors while maintaining effective frequency transmission.
Implementation Method 1
The via structure passes through the first circuit layer, the second circuit layer and the third circuit layer, and is electrically connected to the first ring resonator and the second ring resonator
Implementation Method 2
The first ring resonator has a first ring surrounded area and corresponds to a first cut-off frequency band. The second ring resonator has a second ring surrounded area and corresponds to a second cut-off frequency band
Data Source
AI summary
A three-dimensional (3D) filter and a fabrication method thereof are provided. The 3D filter includes a circuit board, a first ring resonator, a second ring resonator and a via structure. The circuit board includes a first circuit layer, a second circuit layer and a third circuit layer. The third circuit layer is located between the first circuit board and the second circuit board. The first ring resonator is disposed in the first circuit layer and has a first ring surrounded area corresponding to a first cut-off frequency band. The second ring resonator is disposed in the second circuit layer and has a second ring surrounded area corresponding to a second cut-off frequency band. The via structure passes through the first circuit layer, the second circuit layer and the third circuit layer, and is electrically connected to the first ring resonator and the second ring resonator.