Variable Inductor With Movable Coil For High Q-Factor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable inductors face challenges in achieving high inductance variation rates while maintaining a compact design and high quality factor, particularly in multi-band radio frequency communications where different frequency bands require adjustable inductance.
Innovation Solution
A variable inductor design featuring a first lead with a double spiral shape and a second lead that receives difference signals, with a switch controlling the flow of signals to maximize inductance variation, allowing magnetic fluxes to counteract each other, and utilizing transistors for signal control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If inductors are stacked on the substrate to achieve compact design, then the area occupied is reduced, but the distance between the substrate and inductors becomes short resulting in low Q-factor
Solution Approach 1:
The patent transitions from a planar stacked configuration to a three-dimensional structure where the movable inductor can be positioned at an elevated height above the substrate. This vertical positioning allows the inductor to achieve a compact footprint on the substrate while maintaining sufficient distance from the substrate surface, thereby preserving high Q-factor through reduced parasitic coupling.
2Area of stationary object
If inductors are stacked on the substrate to reduce area, then compact design is achieved, but the height of the structure is increased
Solution Approach 1:
The patent employs a movable inductor structure that can dynamically adjust its position between a retracted state (close to substrate) and an extended state (elevated above substrate). This dynamic positioning allows the system to achieve a compact profile when not in use while enabling increased height during operation to optimize electrical performance and reduce parasitic effects.
3Adaptability or versatility
If eddy current is used to vary inductance by opening or closing a switch, then inductance variation is achieved, but the variation rate is low
Solution Approach 1:
The patent replaces the conventional electrical switch-based inductance variation mechanism with a mechanical movable inductor system. By physically moving the inductor to adjust its coupling with the fixed inductor, the system achieves faster and more significant inductance variation rates compared to the limited eddy current modulation method.
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 achieves a high inductance variation rate and improved quality factor, enabling efficient frequency adjustment in radio frequency communications without increasing the device's size or height, suitable for multi-band applications.
Implementation Method 1
the first magnetic flux generated by a first electric current flowing in the first lead in a first direction and a second magnetic flux by a second electric current flowing in the second lead in a second direction from the pair of the difference signals, which are received by the first lead and the second lead, may counteract each other
Data Source
AI summary
A variable inductor is provided, which includes a first lead having both ends to receive a pair of difference signals, a second lead having both ends to receive a pair of the difference signals, and a switch selectively supplying a pair of the difference signals to the second lead by turning on/off according to a control signal. Accordingly, a variable inductor can be implemented that is compact and maximizes the variation rate of inductance.