Inverted Inductive Ground Structures for Common Mode Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic devices face interference issues due to radiated emissions and electromagnetic noise from components like radios and connectors, which degrade signal quality and increase manufacturing complexity and cost, especially as devices become more compact.
Innovation Solution
Integration of planar common mode filters with inverted inductive ground structures into printed circuit boards to reduce radiated emissions and electromagnetic interference, eliminating the need for external filters and chokes, while maintaining device size and improving signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external common mode filters and chokes are used to reduce electromagnetic interference, then signal quality is improved, but device size and manufacturing complexity increase
Solution Approach 1:
The patent merges the common mode filter functionality directly into the printed circuit board ground structure by creating an inverted inductive ground structure that serves both as a ground reference and a common mode filter. This integration eliminates the need for separate external filter components while maintaining electromagnetic interference reduction capabilities, thereby improving signal quality without increasing device complexity or manufacturing complexity
Solution Approach 2:
The inverted inductive ground structure performs multiple functions simultaneously: it provides a ground reference for differential signals, acts as a common mode filter to block electromagnetic interference, and maintains signal transmission properties. This multi-functionality replaces what would traditionally require separate components, reducing both device size and manufacturing complexity while preserving signal quality
2Object-affected harmful factors
If external filters are integrated into the device, then electromagnetic interference is reduced, but device footprint increases
Solution Approach 1:
The filter functionality is merged into the existing PCB ground structure, eliminating the need for separate filter components that would occupy additional space. The inverted inductive ground structure uses the same physical space as the ground plane, thereby reducing electromagnetic interference without increasing device footprint
Solution Approach 2:
The patent utilizes the vertical dimension of the PCB by creating an inverted ground structure that extends in the opposite direction from conventional ground planes. This three-dimensional configuration allows the common mode filter to function within the existing two-dimensional footprint, effectively blocking electromagnetic interference without expanding the device area
3Area of stationary object
If compact device design is implemented, then device size is reduced, but electromagnetic interference between components increases
Solution Approach 1:
The inverted inductive ground structure provides multiple benefits within a compact form: it serves as a ground reference for maintaining signal integrity in compact layouts and simultaneously acts as a common mode filter to block electromagnetic interference between closely spaced components. This allows compact device design without sacrificing electromagnetic compatibility
Solution Approach 2:
The patent applies the inverted ground structure locally at critical interfaces where electromagnetic interference is most problematic, such as near connectors and high-speed signal lines. This targeted approach provides effective interference mitigation in compact designs without requiring the entire device to be redesigned, maintaining small form factor while reducing harmful electromagnetic effects
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 solution effectively mitigates common mode noise, reduces manufacturing complexity and costs, and maintains differential signal transmission properties, enhancing data transmission and device operating ranges without disrupting existing signal protocols.
Implementation Method 1
common mode filters with inverted inductive ground structures
Implementation Method 2
radiated emissions and electromagnetic noise from components
Data Source
AI summary
Systems, methods, and computer-readable media are disclosed for common mode filters with inverted inductive ground structures. In one embodiment, an example printed circuit board may have a first layer with a pair of differential transmission lines, and a common mode filter embedded in the printed circuit board. The common mode filter may include a signal reference structure and an inductive ground structure. The signal reference structure may include a first rectangular portion, and a second rectangular portion having the same dimensions. The second rectangular portion may be separated from the first rectangular portion by a distance. The inductive ground structure may include a first cell having a first conductive line coupled to a first side of the first rectangular portion and a first edge of the common mode filter, and a second cell having a second conductive line coupled to a first side of the second rectangular portion and the first edge.