Band-Pass Filter Circuit Layout for Low Loss and Out-of-Band Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing filters face challenges in achieving smaller size, lower insertion loss, better out-of-band suppression, and higher operating frequency band performance, particularly in communication systems with the rise of Internet of Things and Internet of Vehicles.
Innovation Solution
A filter circuit design with controlled quantities of series and parallel resonance units, utilizing thick and short connecting lines, and three-dimensional inductors to enhance transmission zero points, achieving high out-of-band suppression and miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional filter structures are used, then the filter can achieve basic filtering function, but the size is large and out-of-band suppression is insufficient
Solution Approach 1:
The filter is divided into multiple resonance units (series resonance units and parallel resonance units) that are sequentially arranged. Each resonance unit consists of specific combinations of inductors and capacitors, creating a segmented structure that achieves better out-of-band suppression while maintaining compact size through modular design
Solution Approach 2:
The patent transitions from traditional planar filter layouts to a three-dimensional configuration by stacking resonance units and using vertical connections. This dimensional change allows for more efficient space utilization, achieving smaller footprint while maintaining or improving filtering performance
2Object-affected harmful factors
If more resonance units are added to improve out-of-band suppression, then the filtering performance improves, but the device complexity increases
Solution Approach 1:
Adjacent resonance units are merged by sharing common inductors and capacitors. For example, the last inductor of one series resonance unit serves as the first inductor of the next unit, and capacitors are shared between parallel and series resonance units. This merging reduces the total component count and simplifies the circuit while maintaining multiple transmission zero points for effective out-of-band suppression
Solution Approach 2:
Individual components serve multiple functions: inductors and capacitors are used in both series and parallel resonance configurations, and boundary components between resonance units act as shared elements. This multi-functionality reduces overall component quantity while achieving complex filtering characteristics
3Loss of energy
If conventional connecting lines are used between components, then the layout is simple, but the insertion loss is high
Solution Approach 1:
The connecting lines between inductors and capacitors are designed with locally optimized characteristics - using thicker trace widths and shorter lengths at critical signal paths where current density is highest. This local quality enhancement reduces resistive losses without requiring complete redesign of the entire PCB layout
Solution Approach 2:
Connecting lines utilize three-dimensional PCB routing with multiple layers and vertical vias instead of simple planar connections. This allows for shorter current paths and better impedance control, reducing insertion loss while managing the increased routing complexity through systematic layer assignment
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 improves out-of-band suppression and reduces insertion loss, enabling a band-pass filter with multiple transmission zero points and supports miniaturization and low cost.
Implementation Method 1
each of the at least one parallel branch includes a parallel resonance unit, the series branch includes at least one series resonance unit arranged in sequence
Data Source
AI summary
A filter circuit, a filter, and an electronic device are disclosed. The filter circuit includes: a first port and a second port arranged opposite to each other, a grounding terminal, a series branch between the first port and the second port, and at least one parallel branch connected with the series branch; where the series branch includes at least one series resonance unit arranged in sequence, each of the at least one parallel branch includes a parallel resonance unit, and the parallel resonance unit is connected with the grounding terminal.