RF MEMS Capacitive Switches Research Articles

Design and investigation of a novel variable reactance-based capacitive RF-MEMS switch with multifrequency operation for mmWave applications

Design and investigation of a novel variable reactance-based capacitive RF-MEMS switch with multifrequency operation for mmWave applications

A compact and reconfigurable C-band DGS-based power divider using RF MEMS capacitive switch

This article presents a reconfigurable and compact power divider design that utilizes a combination of defect structures in the ground plane (DGS) and capacitance loading using a unique RF MEMS switch on the sapphire substrate. The combination of these two techniques results in a reduced-size reconfigurable power divider, wherein the length of the quarter-wavelength transmission line is reduced to λ/16 from λ/4, and the higher-order harmonics are suppressed up to 40 GHz. The RF MEMS capacitive switch is designed, and its DC characteristics are simulated in coventorware. The RF characteristics of the designed power divider are simulated in Ansys HFSS 19.2. The power divider utilizing RF MEMS technology has been fabricated through surface micromachining, requiring only four masks for fabrication. According to measurement findings, insertion loss and return loss are 3.57 dB and 24.6 dB (at 4.4 GHz) and 3.82 dB and 22.06 dB (at 5.4 GHz) when the switch is on and off, respectively. The total area of the design is 3.1 mm2 (21.3% of the conventional power divider). The proposed design can suppress harmonics up to the 8th order by 10 dB. These features render it a viable option for employment in Radio Frequency Integrated Circuits (RFICs).

RF-MEMS capacitive switches: enabling transition towards 5G/B5G applications

RF-MEMS capacitive switches: enabling transition towards 5G/B5G applications

Design and Analysis of the Capacitive RF MEMS Switches with Support Pillars.

Conventional parallel capacitive RF MEMS switches have a large impact during the suction phase. In general, RF MEMS switches have to be switched on and off in a considerably fast manner. Increasing the driving voltage enables fast switching but also increases the impact force, which causes the beam membrane to be prone to failure. In the present study, the addition of two support pillars was proposed for slowing down the fall of the beam membrane based on the conventional RF MEMS parallel switch, so as to reduce the impact velocity. As such, a novel RF MEMS switch was designed. Further, simulation software was used to scan and analyze the positioning and height of the support pillars with respect to electromechanical and electromagnetic performance. The simulation results show that the optimal balance of impact velocity and pull-in time was achieved at a height of 0.8 um, a distance of 10 um from the signal line, and an applied voltage of 50 V. The impact velocity was reduced from 1.8 m/s to 1.1 m/s, decreasing by nearly 40%. The turn off time increased from 3.9 us to 4.2 us, representing an increase of only 0.05%. The insertion loss was less than 0.5 dB at 32 GHz, and the isolation was greater than 50 dB at 40 GHz.

An improved design based on a symmetrical toggle shunt capacitive RF-MEMS switch with multiple stable states and Off-state frequency tunability

An improved design based on a symmetrical toggle shunt capacitive RF-MEMS switch with multiple stable states and Off-state frequency tunability

Electromechanical modelling and stress analysis of RF MEMS capacitive shunt switch

This paper presents the simulation results as well as calculated results of a proposed RF MEMS shunt switch with Electro-mechanical modelling and stress gradient characteristics. The analysis is done with three membrane structures such as plane beam, incorporated with and without perforations, and non-uniform meander type beam, these are simulated in the COMSOL Multi-physics tool. The various model analysis are carried out for different values of residual stress gradients such as different structures, materials, and beam thickness. The analysis are characterized that the higher values of stress gradient are not desirable for switching action. By analyzing all the results we have observed that the stress analysis for the non-uniform meandered type switch obtained maximum stress of 35.6 MPa, and center deflection of 0.06 MPa/μm, the deformations of the beam which is the least among the considered switches.

FEM simulation and material selection for enhancing the performance of a RF-MEMS capacitive switch

FEM simulation and material selection for enhancing the performance of a RF-MEMS capacitive switch

Design, simulation and optimization of an RF MEMS capacitive switch to reduce actuation voltage

Design, simulation and optimization of an RF MEMS capacitive switch to reduce actuation voltage

Design and performance analysis of a low-pull-in-voltage RF MEMS shunt switch for millimeter-wave therapy, IoT, and 5G applications

Recent advancements in wireless communication systems utilize miniaturized devices based on microelectromechanical system technology for present and future 5G wireless applications. Nowadays, RF devices are utilizing frequencies up to 30 GHz with substantial signal propagation that leads to a slow data rate. On the other hand, there is a huge spectrum available in the millimeter-wave frequency range of 30–300 GHz. The millimeter-wave spectrum is attractive for the development of smart systems based on 5G technology. In this paper, a low-pull-in-voltage capacitive type RF MEMS switch is proposed to operate at frequencies above 30 GHz. The switch is proposed with a new iterative meandering technique where the span length of each section in the meanders differs relative to the first section. A low pull-in voltage of 1.8 V is achieved with a large capacitance ratio of 63. The switch exhibits low insertion loss of −0.24 dB at 41 GHz and possesses high isolation of −46.7 dB at 38 GHz. The design is validated by comparing the theoretical and simulated results, and the switch can be efficiently utilized for millimeter-wave applications.

Design, Simulation and Analysis of Perforated RF MEMS Capacitive Shunt Switch

Objective: This paper presents the design and simulation of double bridge-type capacitive RF MEMS switch by using FEM Tool. Methods: It is mainly concentrated on a low pull-in voltage, capacitance, and RF analysis. The beam is considered as a gold metal having the length of 595 μm along with the 1μm thickness and the dielectric is taken as Silicon nitride (Si3N4) by using Ashby’s method. The non-uniform meandering technique and perforations are used to reduce the pull-in voltage, by changing different beam thickness, air gap and materials. Results: The pull-in voltage of the proposed RF MEMS switch is 1.2 V. The scattering parameters are simulated by using Ansoft HFSS software. The simulation results of S-parameters such as return loss, insertion losses are, -19.27 dB and -0.20dB. The switch having good isolation is -63.94 dB at 8 GHz. Conclusion: The overall switch is designed with different beam thickness, various gap, and different materials to identify the best performance of the switch for low-frequency applications i.e X-bands.

A novel method for the assessment of surface charge density variance in capacitive RF-MEMS switches

The present paper provides a novel, inexpensive and non-destructive method to assess the surface charge density variance in capacitive RF-MEMS switches. The charge variance evolution can be monitored during charging and discharging processes by measuring the up-state capacitance, in addition to the mean value, providing results directly related to charging failure mechanisms and the prediction of the devices lifetime for unipolar/bipolar actuation. Also, the experimental results can be used to engineer the dielectric film electrical properties in order to control the surface and bulk conductivities according to needed application.

Electromagnetic modelling and analysis of RF MEMS capacitive shunt switch for 5G applications

This paper presents the Electromagnetic modelling and simulation analysis of an RF MEMS Shunt switch. The Sparameters are investigated with different analysis such as changing beam structure, materials, thickness of the beam, and signal dielectric. The pull-in voltage of the proposed switch is obtained as 1.9 V. The RF-performance mainly depends on the up and down state of the switch, these analysis are done in the ANSYS HFSS simulator tool. The evaluated return and insertion losses are −44.7486 dB and −0.9598 dB, and the switch exhibits a good isolation of −49.1809 dB at 43 GHz frequency. RF-Performance is obtained at 26–45 GHz range. So, the proposed switch can be applicable for 5G applications.

Design and Analysis of a Uniform Meander RF MEMS Switch

This paper projected to uniform meander RF MEMS capacitive shunt switch design and analysis. The less pull in voltage is obtained in flexure type membrane by proposed RF MEMS Switch. The materials selection for the dielectric layer and beam is explained in this paper and also shown the performance depends on materials utilized for the design. The good isolation of -31dB is achieved for the pull-in voltage of 11.97V with a spring constant of 2.38N/m is produced by the switch and is obtained by the optimization process at a frequency of 38GHz.

Design and Analysis of Novel RF-MEMS Capacitive Type Shunt Switch for 5G Applications

This paper presents the design and analysis of the RF-MEMS Capacitive type switch. Here, we have proposed different stages of shunt switches for better performance. The objective of the proposed work is to design different beam structures and to calculate pull-in voltage with various gaps, beam thickness, and materials in FEM tool. By decreasing the pull-in voltage we have taken perforations and different meandering techniques (uniform and non-uniform). The material selection impacts the switch performance, here the dielectric material is taken as silicon nitride, the beam material is considered as gold, because of its high conducting material. The pull-in voltage of the proposed non-uniform meander type switch is 1.9 V, the RF-performance is measured in the HFSS and ADS equivalent circuit simulator tools, the return and insertion losses are obtained as −41.74 dB and -0.95 dB at 43 GHz, 40.10 GHz. The switch measured better isolation as – 36.25 dB, -20.55 dB at 20-40 GHz. The switch performance is obtained at 20-50 GHz range, therefore it can be feasible for 5G applications.

Design and Analysis of a Non-Uniform Meander RF MEMS Switch

This paper aimed to design and analysis of non-uniform meander capacitive shunt RF MEMS switch. The less pull in voltage is obtained in flexure type membrane by proposed RF MEMS Switch. The selection of materials for the beam and dielectric layer is expressed in this paper and also shown the performance depends on materials utilized for the design. The high isolation of -31.15dB actuating at the pull-in voltage of 7.69V with a spring constant of 3.28N/m produced the switch and is obtained by the optimization process. Capacitive contact switches have capability of power handling. The actuated switch state provides an excellent isolation. It shorts the ground by RF signal. MEMS technology is the integration of electrical and mechanical components on single platform i.e. substrate [10]. From the literature, various researchers have proposed different RF MEMS Switch, but still there few challenges on optimization of the Switch for best performance. The electromechanical analysis such as Upstate, Downstate capacitances and stress analysis have been carried out. The performance of the switch is analyzed by taking appropriate materials selected by Ashby’s approach. These optimized dimensions are feasible to fabricate. The substrate height, material for the substrate and coplanar waveguides are used for the impendence matching. For obtaining the less pull in voltage overlapping area is to be increased.

Design and analysis of capacitive RF MEMS switch with step structure and meander spring for cellular communication

An electrostatically actuating capacitive RF MEMS switch with a rare step structure and meander spring is designed and analysed in this work. The materials for the dielectric medium between the RF ...

Dielectric Material Selection for High Capacitance Ratio and Low Loss in MEMS Capacitive Switch using Ashby’s Methodology

The performance of the RF MEMS capacitive switch is majorly decided on capacitance ratio and loss in the dielectric layer as they decide the isolation (in dBs) in off condition. The capacitances in a MEMS capacitive switch in pull-up and pull-down states are used for deciding the capacitance ratio. In this article, we have presented a method to find out the best dielectric material using Ashby’s methodology for high capacitance ratio and low loss thus high isolation in switch off condition. Firstly, a database of 10 mostly employed dielectric materials have been created, and then, material indices are derived using material properties such as dielectric constant, resistivity, conductivity, and loss tangent which have been used in the selection of dielectric material. Through the study it is observed that to have a high capacitance ratio and low loss in dielectrics, the down capacitance should always be much greater than pull-up capacitance and tangent loss must be kept at possible minimum. This method will be highly useful in the selection of the best dielectric material by switch designers.

Damping analysis to improve the performance of shunt capacitive RF MEMS switch

This paper describes the significance of the iterative approach and the structure damping analysis which help to get better the performance and validation of shunt capacitive RF MEMS switch. The micro-cantilever based electrostatic ally actuated shunt capacitive RF MEMS switch is designed and after multiple iterations on cantilever structure a modification of the structure is obtained that requires low actuation voltage of 7.3 V for 3 ?m deformation. To validate the structure we have performed the damping analysis for each iteration. The low actuation voltage is a consequence of identifying the critical membrane thickness of 0.7 ?m, and incorporating two slots and holes into the membrane. The holes to the membrane help in stress distribution. We performed the Eigen frequency analysis of the membrane. The RF MEMS switch is micro machined on a CPW transmission line with Gap- Strip-Gap (G-S-G) of 85 ?m - 70 ?m - 85 ?m. The switch RF isolation properties are analyzed with high dielectric constant thin films i.e., AlN, GaAs, and HfO2. For all the dielectric thin films the RF MEMS switch shows a high isolation of -63.2 dB, but there is shift in the radio frequency. Because of presence of the holes in the membrane the switch exhibits a very low insertion loss of -0.12 dB.

Design and analysis of capacitive RF MEMS switch with step structure and meander spring for cellular communication

Design and analysis of capacitive RF MEMS switch with step structure and meander spring for cellular communication

Design of elliptical-shaped reconfigurable patch antenna with shunt capacitive RF-MEMS switch for satellite applications

AbstractIn this paper, non-uniform meandered line shunt capacitive RF-MEMS switch is presented at an elliptical patch etched with a split-ring resonator (SRR) for satellite communication applications. The non-uniform meander line shunt capacitive is a fixed-fixed type of RF-MEMS switch that is introduced in this model antenna. The proposed antenna design is resonated at 10.46 GHz with the return loss of −37.6 dB. The performance evolution of the proposed antenna design is evaluated with and without integrated RF-MEMS switch on the proposed antenna SRR. It is observed that the proposed model at the ON-state switch resonates at 10.57 GHz frequency with the return loss of −30 dB. Similarly, at the OFF-state switch, it resonates at 10.53 GHz frequency with the return loss of −43 dB. Al3N4 (aluminum nitride) is used for the switch as a dielectric material, hence the switch attains higher isolation. The actuation voltage of 7.9 V is required for the switch to actuate from ON to OFF state. The switch attains minimum insertion and return loss which is discussed in further sections. The proposed antenna is fabricated and tested by a vector network analyzer; there is a good agreement between the simulated and measured results.