Planar Inductive Unit Ground Path Design for Impedance Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing planar inductive components face challenges with non-matched impedances due to unwanted ground inductance, which affects the performance of impedance matching networks and can lead to increased footprint and undesired crosstalk effects.
Innovation Solution
A planar inductive unit with a ground path design that includes a second section with a different width and offset in a separate plane, allowing for negative mutual inductance to cancel out ground inductance, and an optional ground shield for reduced losses and footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wide ground lines are used to minimize ground inductance, then ground inductance is reduced, but the footprint area increases significantly
Solution Approach 1:
The ground path transitions from a two-dimensional planar structure to a three-dimensional folded structure by utilizing vertical dimension through folds and bends. This allows the ground path to achieve longer effective length (for lower inductance) within a smaller planar footprint by stacking ground path segments in multiple layers or levels.
Solution Approach 2:
The ground path is folded back on itself multiple times, creating a nested configuration where ground path segments are arranged in a compact, space-efficient manner. The path folds create overlapping or adjacent segments that effectively pack the ground path into a smaller area while maintaining the required electrical length.
2Reliability
If ground path length is increased to reduce ground inductance, then ground inductance decreases, but the device footprint increases
Solution Approach 1:
The ground path utilizes the vertical dimension through folding and bending to achieve longer effective electrical length without proportionally increasing the planar footprint. The folded configuration allows the ground path to extend in multiple directions and levels, effectively packing more length into a compact space.
Solution Approach 2:
The ground path is divided into multiple segments connected through folds and bends. Each segment contributes to the total electrical length while the folded connections allow compact arrangement. This segmentation enables the ground path to achieve required length through distributed segments rather than a single long straight path.
3Ease of manufacture
If conventional planar inductor design is used, then manufacturing is simple, but unwanted ground inductance affects impedance matching performance
Solution Approach 1:
The ground path is folded to create a three-dimensional configuration within a planar substrate, achieving longer effective length for lower inductance without requiring additional manufacturing steps. The folded structure can be implemented using standard PCB fabrication or integrated circuit layer techniques, maintaining manufacturing simplicity while improving 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 solution reduces ground inductance, minimizes footprint by up to 50%, and improves performance at operating frequencies by effectively canceling inductive effects, suitable for various electronic devices including RF amplification stages.
Implementation Method 1
the second section with a second width extending in at least a second plane... the mutual inductance of the at least one winding and the ground path equals a negative inductance of the ground path
Implementation Method 2
an optional ground shield for reduced losses and footprint
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3~4
AI summary
A planar inductive unit having at least one operating frequency is provided. The inductive unit comprises at least one inductor winding (120) having a first width (121) and a centre (122) and being arranged in a first plane. The inductive unit furthermore comprises at least one ground path (200) having a first section (205) extending in the first plane and at least a second section (210) with a second width (211) extending in at least a second plane.