Integrated LC Filter Topology for Compact Branching Filters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing compact mobile communication apparatuses face challenges in miniaturizing branching filters while maintaining desired frequency characteristics, as the number of capacitors increases with the order of filters, making it difficult to achieve size reduction without compromising performance.
Innovation Solution
The proposed LC circuit and filter configuration utilize a specific arrangement of capacitors and inductors, including parallel connections and a stacked structure with dielectric and conductor layers, to minimize size while maintaining desired frequency characteristics, allowing for a high-pass or low-pass filter configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the order of the filter is increased to satisfy desired frequency characteristics, then the filter performance is improved, but the number of capacitors increases and the filter size increases
Solution Approach 1:
The patent merges multiple capacitor functions into a single integrated capacitor structure. Specifically, multiple capacitor elements are combined in parallel between the same two nodes (first and second nodes), creating one capacitor that performs the electrical function of multiple separate capacitors. This integration maintains the required total capacitance value for high-order filter characteristics while occupying the space of only one capacitor component, thereby resolving the contradiction between filter performance and filter size.
Solution Approach 2:
The integrated capacitor structure serves multiple functions simultaneously: it provides the total required capacitance for the high-order filter characteristic, occupies minimal space equivalent to one capacitor, and maintains electrical connectivity at multiple nodes. This multi-functionality allows the filter to achieve high-order performance without proportionally increasing in size.
2Reliability
If multiple capacitors are connected in series to achieve desired capacitance values, then the filter characteristic is satisfied, but the physical length of the signal path increases
Solution Approach 1:
The patent combines multiple capacitor elements into a single integrated capacitor that provides the total required capacitance. By merging parallel capacitor elements into one component located at a single position in the signal path, the design maintains the electrical equivalent of multiple series capacitors while minimizing the physical length of the signal path. The integrated capacitor achieves the desired filter characteristic without extending the signal path length proportionally.
3Volume of stationary object
If more capacitors are used to achieve miniaturization, then the capacitance density increases, but the circuit complexity increases
Solution Approach 1:
The patent integrates multiple capacitor elements into a single capacitor structure, thereby reducing circuit complexity. Instead of implementing multiple separate capacitor components with individual connections and mounting points, the integrated design consolidates these functions into one component. This merging maintains the required total capacitance and electrical characteristics while significantly simplifying the circuit layout, reducing the number of discrete components, and lowering assembly complexity.
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 configuration enables the miniaturization of LC circuits and filters with preserved performance, achieving smaller physical dimensions while maintaining the desired filter characteristics, as demonstrated by simulation results showing reduced total capacitance and favorable frequency responses.
Implementation Method 1
a first capacitor provided between a first connection point and a second connection point, a second capacitor provided between the second connection point and a third connection point, a third capacitor provided between the third connection point and a fourth connection point
Implementation Method 2
a first inductor connected to the second connection point, and a second inductor connected to the third connection point
Data Source
AI summary
An LC circuit includes a first capacitor provided between a first connection point and a second connection point, a second capacitor provided between the second connection point and a third connection point, a third capacitor provided between the third connection point and a fourth connection point, a fourth capacitor provided between the first connection point and the third connection point, a fifth capacitor provided between the second connection point and the fourth connection point, a first inductor connected to the second connection point, and a second inductor connected to the third connection point.