MEMS Variable Inductor Structure for Tunable Inductance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional inductors have fixed inductance values, limiting their application due to their inability to vary inductance after manufacturing.
Innovation Solution
A variable inductor or inductor module utilizing micro-electromechanical system (MEMS) structures to change inductor spacing and spacing between inductor metal and a substrate, allowing for variance in inductance value by adjusting the shape of the inductor using an electrostatic force-driven MEMS driver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a general inductor is manufactured with predetermined parameters, then the inductor has a fixed inductance value, but its usefulness is limited due to inability to vary inductance
Solution Approach 1:
The patent applies the dynamics principle by making the inductor coil movable relative to the substrate through a MEMS actuator. The coil can be dynamically positioned at different heights above the substrate, changing the inductance value from a fixed state to a variable state. This allows the inductor to adapt its inductance according to operational requirements while maintaining a relatively simple overall structure.
Solution Approach 2:
The patent implements parameter changes by varying the physical position of the inductor coil (specifically, the distance between the coil and the substrate) to change the inductance value. By controlling the height of the coil above the substrate through electrostatic actuation, the electrical parameter (inductance) is changed without altering the fundamental structure of the inductor.
2Adaptability or versatility
If MEMS structures are added to enable inductance variation, then inductance can be changed after manufacturing, but the device complexity increases
Solution Approach 1:
The patent replaces a potentially complex mechanical adjustment system with a MEMS (micro-electromechanical system) actuator. The MEMS device uses electrostatic fields to achieve precise mechanical displacement of the inductor coil, substituting what could have been a bulky mechanical screw or lever system with a miniaturized electrical-mechanical system that integrates seamlessly with IC technology.
Solution Approach 2:
The MEMS actuator serves multiple functions: it provides the mechanical force to move the coil, acts as a controllable switch for inductance tuning, and can be integrated with standard IC fabrication processes. This multi-functionality reduces the need for separate components and simplifies the overall device architecture despite adding tuning capability.
3Manufacturing precision
If the distance between inductor coil and substrate is increased, then inductance value changes, but the inductor spacing and substrate spacing must be precisely controlled
Solution Approach 1:
The MEMS actuator employs electrostatic attraction between charged plates to automatically hold the inductor coil at a precise distance from the substrate. The electrostatic force itself serves as the positioning mechanism, where the equilibrium position is determined by the balance between electrostatic attraction and mechanical restoring forces. This self-service positioning eliminates the need for complex external positioning mechanisms and achieves high precision through the inherent physics of the system.
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
Enables the inductor to have a variable inductance, enhancing its usefulness in applications such as tunable VCOs and LNA used in multi-frequency band ICs.
Implementation Method 1
a micro-electromechanical system (MEMS) driver that responds to an electrostatic force configured to be turned on or off in response to a control signal, and is configured to raise increase a distance between at least part of the inductor coil and the substrate
Data Source
AI summary
Disclosed is a variable inductor or inductor module with a varying inductance, wherein the variable inductor or inductor module changes inductor ring spacing and the distance between the inductor and a substrate using a MEMS driver, thereby enabling variances in the inductance.