RF MEMS Switch Comb Actuator Prevents Sticking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional RF MEMS switches face issues with sticking between the interconnect and substrate, leading to increased insertion loss and power consumption due to close fabrication and multiple contact points.
Innovation Solution
An RF MEMS switch design that generates electrostatic force between a fixing portion and an actuator using a comb structure, allowing for low-voltage operation and preventing sticking, with a single contact point to reduce insertion loss and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the interconnect is fabricated in close relation with the substrate, then the device size is reduced, but the interconnect and substrate may stick to each other causing increased insertion loss and power consumption
Solution Approach 1:
The interconnect is divided into multiple segments with gaps between them, allowing the interconnect to be flexible and maintain distance from the substrate while still achieving compact device size. The segmented structure prevents sticking by creating air gaps between the interconnect segments and substrate surface.
Solution Approach 2:
The interconnect is designed with a three-dimensional structure including vertical gaps from the substrate and horizontal gaps between segments. This multi-dimensional spacing approach allows compact footprint while maintaining sufficient clearance to prevent sticking and reduce parasitic effects.
2Reliability
If both ends of the interconnect come in contact with the signal lines, then the connection is established, but the contact resistance increases causing increased insertion loss and power consumption
Solution Approach 1:
One end of the interconnect is extracted from contact with the signal line, leaving only a single contact point at the other end. This reduces the contact area and number of contact interfaces, thereby minimizing contact resistance and associated energy losses while maintaining functional connectivity.
3Ease of manufacture
If a conventional interconnect structure is used, then the fabrication is simple, but the actuator may stick to the substrate and performance deteriorates
Solution Approach 1:
The interconnect is designed as a flexible, dynamic structure that can deform and maintain spacing from the substrate during actuation. This dynamic configuration allows the interconnect to follow the actuator motion while preventing contact with the substrate, eliminating sticking issues without complex fabrication.
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 prevents actuator sticking during fabrication, reduces insertion loss, and lowers power consumption by utilizing a comb structure for electrostatic actuation with a single contact point, enhancing operational efficiency.
Implementation Method 1
electrostatic force is generated between a fixing portion and an actuator so that the actuator is prevented from sticking to a substrate
Data Source
AI summary
A vertical comb actuator radio frequency (RF) micro-electro-mechanical system (MEMS) switch. The RF MEMS switch includes a substrate; first and second signal lines spaced at a predetermined interval from each other and deposited on an upper surface of the substrate; an actuator positioned over the first and second signal lines when viewed from the upper surface of the substrate and spaced at a predetermined interval from the first and second signal lines; and a fixing portion positioned over the actuator when viewed from the upper surface of the substrate, wherein the fixing portion permits the actuator to come in contact with the first and second signal lines when a predetermined driving voltage is applied. Thus, it is possible to prevent the actuator from sticking to the substrate. In addition, the RF MEMS switch can be operated with a low voltage and insertion loss and power loss can be reduced.