Thermal Management in RF MEMS Ohmic Switches

2007 ◽  
Author(s):  
Ryszard J. Pryputniewicz
Keyword(s):  
Thermal Management ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Electrical Contact ◽  
Internal Resistance ◽  
Electrical Signal ◽  
Joule Heat ◽  
Mems Switch ◽  
Heat Effects ◽  
Functional Operation

Today, an ideal microelectromechanical systems (MEMS) switch is no longer a designer’s dream, yet electrothermomechanical (ETM) effects still limit the design possibilities and may adversely affect reliability of microswitches, especially the Ohmic-type cantilever contact switches. The ETM effects are a result of Joule heat generated at the switch contact areas (i.e., electrical interfaces). This heat is due to an electrical signal passing through a microswitch, internal resistance of contact materials, and characteristics of the electrical contact interface. It significantly raises temperature of a microswitch, thus adversely affecting mechanical and electrical properties of the contacts, leading to their wear or even welding, which is a major reliability issue. Fundamental research is being performed to minimize Joule heat effects in the electrical interface area, thus improving the microswitch performance and reliability. Thermal analysis conducted computationally on an Ohmic-type RF MEMS switch indicate heat affected zones (HAZ) and the influence that various parameters have on those zones. Such analysis facilitates mitigation of thermal management issues that may otherwise be detrimental to functional operation of a microswitch.

Simultaneous Electrical and Thermal Modeling of a Contact-Type RF MEMS Switch

2003 ◽  
Author(s):  
Brian Jensen ◽  
Zhongde Wang ◽  
Kazuhiro Saitou ◽  
John L. Volakis ◽  
Katsuo Kurabayashi
Keyword(s):  
Contact Resistance ◽  
Direct Contact ◽  
Rf Mems ◽  
Bulk Material ◽  
Thermal Contact ◽  
Electrical Contact ◽  
Maximum Temperature ◽  
Electrical Contact Resistance ◽  
Rf Mems Switch ◽  
Mems Switch

Improving the power handling capability of direct contact RF MEMS switches requires a knowledge of conditions at the contact. This paper models the temperature rise in a direct contact RF MEMS switch, including the effects of electrical and thermal contact resistance. The maximum temperature in the beam is found to depend strongly on the power dissipation at the contact, with almost no contribution from dissipation due to currents in the rest of the switch. Moreover, the maximum temperature is found to exceed the limit for metal softening for a significant range of values of thermal and electrical contact resistance. Since local contact asperity temperature can be hundreds of degrees higher than the bulk material temperature modeled here, these results underscore the importance of understanding and controlling thermal and electrical contact resistance in the switch.

Optimization of Contact Dynamics for an RF MEMS Switch

2002 ◽  
Author(s):  
Ryszard J. Pryputniewicz ◽  
Cosme Furlong ◽  
Emily J. Pryputniewicz
Keyword(s):  
Material Properties ◽  
Rf Mems ◽  
Contact Dynamics ◽  
Experimental Characterization ◽  
Simple Analytical Model ◽  
Rf Mems Switch ◽  
Mems Switch ◽  
Resistive Switches ◽  
Functional Operation

Functional operation of RF MEMS resistive switches depends on dynamic characteristics of the cantilever contacts. Characteristics of these contacts, in turn, depend on parameters defining their shape and dimensions, material properties, boundary conditions, and actuation voltages. In this paper, a simple analytical model is presented and used to develop an understanding of the switch behavior. In addition, uncertainties corresponding to this model are also determined to quantitatively show the influence that various parameters defining the cantilever contact have on its dynamics which, in turn, influences performance of the RF MEMS switch. This performance can be optimized with the objective of achieving resonance frequency within, e.g., 1% of the desired value while constraining the nominal dimensions and finding the optimum set of uncertainties in these dimensions. Analytical results correlate well with the preliminary experimental characterization of the contacts.

scholarly journals Low-Voltage and High-Reliability RF MEMS Switch with Combined Electrothermal and Electrostatic Actuation

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1237
Author(s):  
Yong Zhu ◽  
Jitendra Pal
Keyword(s):  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Low Voltage ◽  
High Reliability ◽  
Actuation Voltage ◽  
Electrostatic Actuation ◽  
Mems Switch ◽  
Thermal Actuation ◽  
Electrothermal Actuation ◽  
Power Handling Capability

In this paper, we report a novel laterally actuated Radio Frequency (RF) Microelectromechanical Systems (MEMS) switch, which is based on a combination of electrothermal actuation and electrostatic latching hold. The switch takes the advantages of both actuation mechanisms: large actuation force, low actuation voltage, and high reliability of the thermal actuation for initial movement; and low power consumption of the electrostatic actuation for holding the switch in position in ON state. The switch with an initial switch gap of 7 µm has an electrothermal actuation voltage of 7 V and an electrostatic holding voltage of 21 V. The switch achieves superior RF performances: the measured insertion loss is −0.73 dB at 6 GHz, whereas the isolation is −46 dB at 6 GHz. In addition, the switch shows high reliability and power handling capability: the switch can operate up to 10 million cycles without failure with 1 W power applied to its signal line.

scholarly journals High-performance inline RF MEMS switch for application in 5G mobile networks

2021 ◽  
Vol 2086 (1) ◽  
pp. 012068
Author(s):  
A V Tkachenko ◽  
I E Lysenko ◽  
A V Kovalev ◽  
D V Vertyanov
Keyword(s):  
Mobile Networks ◽  
High Performance ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Coplanar Waveguide ◽  
Satellite Communications ◽  
Elastic Suspension ◽  
Rf Mems Switch ◽  
Mems Switch ◽  
5G Mobile Networks

Abstract This article presents the results of the design and analysis of a radio-frequency switch made using microelectromechanical systems technology. The device is the capacitive switch with a hybrid type of contact, in which the movable electrode of the structure – the metal membrane is part of the microwave signal line of the coplanar waveguide. The switch design is characterized by a high capacitance ratio and low contact resistance. The zig-zag elastic suspension is used to reduce the value of the pull-down voltage – 2 V and the switching time ∼ 7 us. The central resonant frequency of the switch is 3.8 GHz. In this case, in the open state, the value of the insertion loss is not more than -0.2 dB and the isolation value in the close state is not less than -55 dB. The effective frequency range is the S-band, as well as the C-, X- and Ku-band, in which the isolation value is at least -30 dB. The presented inline RF MEMS switch is suitable for use in various types of ground and satellite communications, in particular for devices and systems of 5G mobile networks.

Structural Dynamics of an RF MEMS Switch

2005 ◽  
Author(s):  
Hartono Sumali ◽  
Jaron D. Kuppers ◽  
David A. Czaplewski ◽  
Jordan E. Massad ◽  
Christopher W. Dyck
Keyword(s):  
Rf Mems ◽  
Actuation Voltage ◽  
Three Dimensional ◽  
Electrostatic Actuation ◽  
Electrical Signal ◽  
Laser Doppler Velocimeter ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Rf Mems Switch ◽  
Mems Switch

The radio-frequency micro-electromechanical system (RF MEMS) switch comprises a plate suspended by four double-cantilever springs. When electrostatic actuation is applied, the plate moves toward the substrate and closes the switch. This article discusses how simulation and experimental methods improve the performance of the switch by suppressing mechanical rebounds and thus electrical signal discontinuities. To accurately simulate the mechanical motion of the switch, a high-fidelity three-dimensional finite element model is created to couple the solid dynamics with the electrostatic actuation. The displacement of the switch at various points is measured using a laser Doppler velocimeter through a microscope. The operational deflection shapes agree with the model. The three-dimensional model produces the necessary information for an effective one-dimensional model. The latter model is used to calculate an actuation voltage waveform to minimize switch velocity at closure, thereby suppressing switch rebound. The waveforms can be refined experimentally to compensate for switch property variations. Laboratory tests indicate that the waveform suppresses or eliminates rebound events.

Mechanical Properties of Al-3%Ti Thin Film for Reliability Analysis of RF MEMS Switch

2006 ◽  
Vol 306-308 ◽  
pp. 1319-1324 ◽  
Author(s):  
Jun Hyub Park ◽  
Yun Jae Kim ◽  
Sung Hoon Choa
Keyword(s):  
Thin Film ◽  
Experimental Method ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Tensile Loading ◽  
Tensile Tests ◽  
Measuring System ◽  
Rf Switch ◽  
Mems Switch ◽  
Loading System

This paper presents a novel experimental method to investigate the strength of material, Al-3%Ti, which is commonly used in RF(radio frequency) microelectromechanical systems(MEMS) switch. The experimental method involves the development of a new tensile loading system. The new tensile loading system has a load cell with maximum capacity of 0.5N and a non-contact position measuring system based on the principle of capacitance micrometry with 0.1nm resolution for displacement measurement. A voice coil of audio speaker is used as the actuator of the loading system. And new specimen was designed and fabricated to easily manipulate, align and grip a thin-film for a tensile and fatigue test. The material used in this study was Al-3%Ti thin film, which was used in RF switch. The thickness and width of the thin film of specimen are 1.1µm and 480µm, respectively. The holes at center of grip end are able to make alignment and gripping easy. The bridges are to remove the side supports easily and extract specimen from wafer without sawing. Tensile tests were performed on 5 specimens. The ultimate strength of Al-3%Ti was 144MPa.

The low-complexity RF MEMS switch at EADS: an overview

2011 ◽  
Vol 3 (5) ◽  
pp. 499-508 ◽  
Author(s):  
Bernhard Schoenlinner ◽  
Armin Stehle ◽  
Christian Siegel ◽  
William Gautier ◽  
Benedikt Schulte ◽  
...  
Keyword(s):  
Microelectromechanical Systems ◽  
Silicon Oxide ◽  
Rf Mems ◽  
Low Cost ◽  
Low Complexity ◽  
Phase Shifters ◽  
Experimental Investigations ◽  
Rf Mems Switch ◽  
Capacitive Switch ◽  
Mems Switch

This paper gives an overview of the low-complexity radio frequency microelectromechanical systems (RF MEMS) switch concept and technology of EADS Innovation Works in Germany. Starting in 2003, a capacitive switch concept, which is unique in several aspects, was developed to address specific needs in the aeronautic and space. Thermally grown silicon oxide as dielectric layer, the silicon substrate as actuation electrode, and a conductive zone realized by ion implantation make the EADS RF MEMS switch a very simple, low-cost, and reliable approach. In this document, data on experimental investigations are presented, which demonstrate outstanding performance figures in terms of insertion loss, isolation, frequency range, bandwidth, RF-power handling, and robustness with respect to thermal load. Based on this concept, numerous different circuits in particular single-pole single-throws (SPSTs), single-pole multi-throws (SPMTs), tunable filters, phase shifters, and electronically steerable antennas between 6 and 100 GHz have been designed, fabricated, and characterized.

Flexible Circuit-Based RF MEMS Switches

2001 ◽  
Author(s):  
Chunjun Wang ◽  
Ramesh Ramadoss ◽  
Simone Lee ◽  
K. C. Gupta ◽  
Victor M. Bright ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Low Cost ◽  
Polyimide Film ◽  
Circuit Board ◽  
Large Area ◽  
Mems Switches ◽  
Mems Switch ◽  
Rf Mems Switches

Abstract This paper describes a new microelectromechanical systems (MEMS) switch fabricated using flexible circuit technologies. Hundreds of such switches can be laminated onto a large-area printed circuit board (PCB) with other RF devices and circuits. The switches are fabricated using low-cost, low-loss flexible circuit material Kapton-E polyimide film. Switches with actuation voltages as low as 73 V are reported.

scholarly journals Novel Test Fixture for Characterizing MEMS Switch Microcontact Reliability and Performance

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 579 ◽  
Author(s):  
Protap Mahanta ◽  
Farhana Anwar ◽  
Ronald Coutu
Keyword(s):  
Microelectromechanical Systems ◽  
Electrical Contact ◽  
Mems Devices ◽  
Closing Time ◽  
Test Fixture ◽  
Mems Switches ◽  
Mems Switch ◽  
Wide Range ◽  
And Performance ◽  
Hot Switching

In microelectromechanical systems (MEMS) switches, the microcontact is crucial in determining reliability and performance. In the past, actual MEMS devices and atomic force microscopes (AFM)/scanning probe microscopes (SPM)/nanoindentation-based test fixtures have been used to collect relevant microcontact data. In this work, we designed a unique microcontact support structure for improved post-mortem analysis. The effects of contact closure timing on various switching conditions (e.g., cold-switching and hot-switching) was investigated with respect to the test signal. Mechanical contact closing time was found to be approximately 1 us for the contact force ranging from 10–900 μN. On the other hand, for the 1 V and 10 mA circuit condition, electrical contact closing time was about 0.2 ms. The test fixture will be used to characterize contact resistance and force performance and reliability associated with wide range of contact materials and geometries that will facilitate reliable, robust microswitch designs for future direct current (DC) and radio frequency (RF) applications.

A Triple Channel High Rejection RF MEMS Switched Filter Bank

2011 ◽  
Vol 483 ◽  
pp. 132-136
Author(s):  
Yuan Wei Yu ◽  
J. Zhu ◽  
Yi Shi ◽  
Jian Yu
Keyword(s):  
Filter Bank ◽  
Tuning Range ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Fractional Bandwidth ◽  
Mems Switch ◽  
Microstrip Filters ◽  
The Individual ◽  
High Rejection ◽  
Individual Series

This paper presents a bandpass switchable filter for 6–11GHz applications which is housed in a machined aluminum chassis. The circuit consists of three fixed interdigital microstrip filters and two single-pole triple-throw (SP3T) microelectromechanical systems (MEMS) switching networks achieved by the individual series-shunt MEMS switch chips. A tuning range of 36.6% was achieved from 6.7 to 9.7 GHz with a fractional bandwidth of 21.1±2.7%, with low mid-band insertion loss ranging from 2.6 dB to 3.0 dB. Rejection is below -50 dB in most cases and skirt slopes are more than 50 dB/GHz at both lower and higher stopband.

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