scholarly journals Performance Comparison Of Shunt Rf Mems Switches

Author(s):  
S Girish Gandhi, I Govardhani, M Venkata Narayana, K Sarat Kumar

This is an attempt to compare three different shunt configured RF MEMS switches which offers a choice for applications in satellite and antennas. Advanced RF communication domain demands for design and modeling of RF MEMS switch which provides extremely reduced pull-in voltage, better isolation, low insertion loss, and with greater reliability. The proposed work manages with comparison of design modeling and performance of three different shunt configured RF MEMS switches. The proposed shunt configured RF MEMS switches are designed with different dimensions with different meandering techniques with perforations on beam structure helps in reducing the amount of voltage required for actuation of switch which is known as pull-in voltage. Comparative study of three different RF MEMS switches which involves in conducting electromechanical analysis are carried out using COMSOL multi physics tool and electromagnetic analysis are carried out using HFSS tool. Moreover the comparative study involves in comparing the values of pull-in voltage, switching time and capacitance, stress, insertion loss, return loss and isolation of three different RF MEMS switches. Proposed first switch model derives pull-in voltage of 16.9v with the switching time of 1.2µs, isolation of 47.70 dB at 5GHz and insertion loss of 0.0865 dB and return loss of 41.55 dB. Proposed second switch model derives pull-in voltage of 18.5v with the switching time of 2.5µs, isolation of 37.20 dB at 8GHz and insertion loss of 0.1177 dB and return loss of 38.60 dB. Proposed third switch model delivers pull-in voltage of 18.75v with the switching time of 2.56µs, isolation of 44.1552 dB at 8GHz and insertion loss of 0.0985 dB and return loss of 42.1004 dB.

Author(s):  
David I. Forehand ◽  
Charles L. Goldsmith

Wafer-level micro-encapsulation is an innovative, low-cost, wafer-level packaging method for encapsulating RF MEMS switches. This zero-level packaging technique has demonstrated 0.04 dB package added insertion loss at 35 GHz. This article overviews the processes, measurements, and testing methods used for determining the integrity and performance of individual encapsulated RF MEMS packages.


2020 ◽  
Vol 12 ◽  
Author(s):  
Pampa Debnath ◽  
Ujjwal Mondal ◽  
Arpan Deyasi

Aim:: Computation of loss factors for one-bit RF MEMS switch over Ku, K and Ka-band for two different insulating substrates. Objective:: Numerical investigation of return loss, insertion loss, isolation loss are computed under both actuated and unactuated states for two different insulating substrates of the 1-bit RF MEMS switch, and corresponding up and down-capacitances are obtained. Methods:: The unique characteristics of a 1-bit RF MEMS switch of providing higher return loss under both actuated and unactuated states and also of isolation loss with negligible insertion loss makes it as a prime candidate for phase shifter application. This is presented in this manuscript with a keen focus on improvement capability by changing transmission line width, and also of overlap area; where dielectric constant of the substrate also plays a vital role. Results:: The present work exhibits very low down-capacitance over the spectrum whereas considerable amount of up-capacitance. Also when overall performance in terms of all loss parameters are considered, switch provides very low insertion loss, good return loss under actuated state and standard isolation loss. Conclusion:: Reduction of transmission line width of about 33% improved the performance of the switch by increasing isolation loss. Isolation loss of -40 dB is obtained at actuated condition in higher microwave spectra for SiO 2 at higher overlap area. Down capacitance of ~ 1dB is obtained which is novel as compared with other published literature. Moreover, a better combination of both return loss, isolation loss and insertion loss are reported in this present work compared with all other published data so far.


Author(s):  
Lei L. Mercado ◽  
Shun-Meen Kuo ◽  
Tien-Yu Tom Lee ◽  
Russ Lee

RF MEMS switches offer significant performance advantages in high frequency RF applications. The switches are actuated by electrostatic force when voltage was applied to the electrodes. Such devices provide high isolation when open and low contact resistance when closed. However, during the packaging process, there are various possible failure modes that may affect the switch yield and performance. The RF MEMS switches were first placed in a package and went through lid seal at 320°C. The assembled packages were then attached to a printed circuit board at 220°C. During the process, some switches failed due to electrical shorting. More interestingly, more failures were observed at the lower temperature of 220°C rather than 320°C. The failure mode was associated with the shorting bar and the cantilever design. Finite element simulations and simplified analytical solutions were used to understand the mechanics driving the behaviors. Simulation results have shown excellent agreement with experimental observations and measurements. Various solutions in package configurations were explored to overcome the hurdles in MEMS packaging and achieve better yield and performance.


Author(s):  
Chris Brown ◽  
Jacqueline Krim ◽  
Art Morris

RF MEMS switch lifetimes are limited by stiction of the moving components and degradation of the metal to metal contact points during cycling. Currently, maximum switch lifetimes are around 10 to 25 billion cycles. Past experimentation has shown that some stiction problems can be overcome by carefully controlling the operating parameters, but problems at the contact points remain [1]. It is believed that by developing a set of tribological design rules which limit the factors leading to catastrophic failure, switches can operate in excess of 100 billion cycles. Recent research has quantified the reliability and durability of gold contact points on RF MEMS switches as a function of current [2]. Most experimentation on RF MEMS switches has focused on controlling the operating parameters such as current, voltage, electrode materials, contact area, switching mode and force; however, limited work has been performed on a single device type in multiple environmentally controlled testing conditions such as vacuum, cryogenic temperatures, etc. This presentation will discuss performance of the wiSpry RF MEMS switch focusing on quantification of device reliability and failure mechanisms under various atmospheric and temperature conditions. Environmental testing conditions include switching in open air, vacuum and inert gasses, in temperatures ranging from 294 K to 4 K.


In this paper, we have proposed a reconfigurable antenna using micro mechanical actuation switches for K and Ku-band applications. Overall two identical cantilever micro mechanical switches (S1 & S2 ) are used to design reconfigurable patch antenna. The switches are working by electrostatic actuation mechanism. With the switches, overall the antenna is offering four resonant frequencies based on the switches ON/OFF condition. The Micro mechanical switches are offering an isolation loss of -18.5dB and an insertion loss of -1dB. The switch requires a DC actuation voltages of 6V. The Proposed reconfigurable antenna is resonating at four different frequencies based on the different switching conditions of RF MEMS switches. If S1 & S2 both are ON the antenna is resonating at 16.9GHZ, if S1 -ON & S2 -OFF the antenna is resonating at 47.3GHZ & 59.1GHZ, if S1 -OFF & S2 -ON the antenna is resonating at 28.4GHZ, if S1 -OFF & S2 -OFF the antenna is resonating at 27.9GHZ


Author(s):  
Seung Min Yeo ◽  
Spyros I. Tseregounis ◽  
Andreas A. Polycarpou ◽  
Adam Fruehling ◽  
Dimitrios Peroulis

Topographical changes within the contact area as a function of cycling could be a critical factor causing failure and reliability issues in RF MEMS switch operation. In this paper, gold-to-gold contact, cantilever-type RF MEMS switches were tested (cold-switching mode) for different number of cycles, namely, 10, 102, 103, 104, 105, and 106. After the cycling tests, the contact area of each switch was scanned using optical microscopy, scanning electron microscopy and atomic force microscopy to quantify the exact gold-to-gold contact surface changes, leading to adhesion failures (at about 106 cycles). Detailed roughness analysis was carried out to better quantify topographical changes on the contact surface and relate them to failures. It was found that the material transfer from the top beam to the bottom substrate was dominant, and observed after only few cycles. Adhesion failure of gold-to-gold contact switches could be attributed to large protrusions formed on the bottom surface as the switch cycles over 105 times.


Author(s):  
Peter A. Kolis ◽  
Marisol Koslowski ◽  
Anil K. Bajaj

We present simulations of the dynamic response of radio frequency micro-electro-mechanical-systems (RF-MEMS) switches undergoing creep deformation. The model includes a microscale-informed Coble creep formulation incorporated in a beam model of an electrostatically actuated RF-MEMS switch, and it is solved using a Ritz-Galerkin based modal expansion. The resulting effects on the long-term device behavior as well as the implications of uncertainty in the device geometry and material parameters are studied. We find that the addition of creep to the beam model results in an undesired degradation of the device performance, as evidenced by decreases in the closing and release voltages.


2018 ◽  
Vol 32 (30) ◽  
pp. 1850362
Author(s):  
Lei Han ◽  
Shen Xiao

In this paper, design, fabrication and measurements of a novel single-pole-double-throw three-state RF MEMS switch based on silicon substrate are presented. The RF MEMS switch consists of two UV-shaped beam push–pull thermal actuators which have three states of ON, OFF and Deep-OFF by using current actuation. When the switch is at Deep-OFF state, it can provide a higher isolation. The switch is fabricated by MetalMUMPs process. The measurement results show that, to the proposed single-pole-double-throw RF MEMS switch, when Switch I is at the ON state and Switch II is at the OFF state, the return loss is better than −16 dB, the insertion loss of Port1 and Port2 is less than −0.9 dB and the isolation of Port3 and Port1 is better than −22 dB at the frequency range from 8 GHz to 12 GHz. When Switch I is at the ON state and the actuator of Switch II is pulled back, which is called the Deep-OFF state, the return loss of Port1 is better than −15.5 dB, the insertion loss of Port1 and Port2 is better than −0.8 dB, and the isolation of Port3 and Port1 is better than −23.5 dB can be achieved at the frequency range from 8 GHz to 12 GHz.


2013 ◽  
Vol 411-414 ◽  
pp. 1674-1679 ◽  
Author(s):  
Zhong Liang Deng ◽  
Hua Gong ◽  
Sen Fan ◽  
Cai Hu Chen

This article describes the design of a microstrip patch antenna with radiation pattern reconfigurable characteristic, where two monolithically integrated MEMS switches are utilized. By changing the physical dimension of the antenna, its radiation pattern could be changed. Moreover, we present detailed structures of these RF MEMS switches, whose isolation and insertion loss are-23.12 dB and-0.09 dB at operating frequency, respectively. And the resonant frequency of the antenna is 35.4 GHz and the bandwidth is 6.69%. All the results are simulated.


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