Shunt Capacitive Switch Research Articles

CPW Tunable Band-Pass Filter Based on RF MEMS Capacitive Shunt and Series Switches

CPW Tunable Band-Pass Filter Based on RF MEMS Capacitive Shunt and Series Switches

Integrating RF MEMS Switch on Array Antenna to Achieve Reconfigurability in Wideband Application

Reconfigurable multi-band antennas are highly used for commercial as well as military purposes as a single antenna could be reconfigured dynamically to send and the receive multiple signals of different frequency simultaneously. In this work an antenna array is designed and integrated with RF MEMS shunt capacitive switch over it, for the applications of S,C,X-band in the frequency range of 2-12GHz. A membrane that can move freely over a coplanar waveguide serves as the MEMS switch. Here, a double meander tuned dual beam arrangement is used to increase switch isolation. Electrostatic mechanisms are used for actuators due to their low power requirements, compact design, and quick switching. By the simulation result, The beam starts to bend from 0.60793mm to 0.4116mm at the voltage 1.78492mV to 57.7382mV and it provides capacitance at 1.435pF to 1.597nF. It was noticed that the insertion loss (S21) and the return loss (S11) of a MEMS switch are around -0.079 dB and 20.618 dB correspondingly, in order to have a good switching characteristic in the up state. The switch has an insertion loss (S21) of -31.307 dB and return loss (S11) of about -0.256 dB in the up state thus exhibiting good switch characteristics. The RF MEMS shunt capacitive switch is integrated on the predesigned antenna array the dynamically shifting of the switch from on state to off state helps achieving the reconfigurability in the antenna array. Such antennas are applicable in spaceborne radar, communication satellites, unmanned aerial vehicles, unmanned aircraft system and various other communication as well as sensing applications.

RF MEMS capacitive shunt switch for low loss applications

Radio frequency (RF) microelectromechanical system capacitive shunt switch with metal-to-metal contact is designed, fabricated and tested with the aim of having very low insertion loss (<0.2 dB) for high frequencies. The switch is designed with two identical parallel side beams with no overlapping with the signal line. This design has an added advantage of removing the self-actuation issues at high RF power. The measured isolation offered by the switch is greater than 40 dB at the resonant frequency, and the resonant frequency can be easily tuned by changing the length of a thin floating metal layer beneath the signal line.

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.

Primena višekriterijumske optimizacije zasnovana na verovatnoći u tehnologiji materijala

Introduction/purpose: Althought many methods have been proposed to deal with the problem of material selection, there are inherent defects of additive algorithms and subjective factors in such algorithms. Recently, a probability-based multi-objective optimization was developed to solve the inherent shortcomings of the previous methods, which introduces a novel concept of preferable probability to reflect the preference degree of the candidate in the optimization. In this paper, the new method is utilized to conduct an optimal scheme of the switching material of the RF-MEMS shunt capacitive switch, the sintering parameters of natural hydroxyapatite and the optimal design of the connecting claw jig. Methods: All performance utility indicators of candidate materials are divided into two groups, i.e., beneficial or unbeneficial types for the selection process; each performance utility indicator contributes quantitatively to a partial preferable probability and the product of all partial preferable probabilities makes the total preferable probability of a candidate, which transfers a multi-objective optimization problem into a single-objective optimization one and represents a uniquely decisive index in the competitive selection process. Results: Cu is the appropriate material in the material selection for RF - MEMS shunt capacitive switches; the optimal sintering parameters of natural hydroxyapatite are at 1100°C and 0 compaction pressure; and the optimal scheme is scheme No 1 for the optimal design of a connecting claw jig. Conclusion: The probability-based multi-objective optimization can be easily used to deal with an optimal problem objectively in material engineering.

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.

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, Analysis and Simulation of RF MEMS Capacitive Shunt Switch with Perforations for Ka-Band Applications

Design, Analysis and Simulation of RF MEMS Capacitive Shunt Switch with Perforations for Ka-Band 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.

An intensive approach to optimize capacitive type RF MEMS shunt switch

Optimization of the RF MEMS switch is essential to enhance its performance characteristics at high frequency Millimeterwave applications. Many optimization techniques have been proposed based on design factors and output responses but not confined with the resonant frequency of RF transmission signal. In this paper, a novel optimization technique is proposed using Multiphysics FEM simulations based on electromagnetic and electromechanical studies. A novel Capacitive type of RF MEMS shunt switch is designed by using iterative meander technique and optimized at the resonant frequency of 41 ​GHz which can efficiently used for millimeter wave applications up to 60 ​GHz. The proposed optimization model which is a novel bottom – up approach consists of intermediate steps for optimization of various layers of switch from substrate to beam. The CPW transmission line with 60/100/60 as G/S/G and having 0.5 ​μm as thickness is considered to allow the frequencies up to 60 ​GHz. The width of the suspended Beam of switch is optimized to obtain up-state capacitance of 37 ​fF which allows the RF signal at 41 ​GHz. Parametric analysis has been carried out to obtain optimized thickness of each layer. Two types of switches other than Fixed – Fixed beam are designed using meandering technique to reduce pull in voltage. Among these the proposed Iterative meander switch shows very low pull in voltage of 1.4 ​V and also shows good return loss of −48.9 ​dB at 41 ​GHz and high isolation of −48.42 ​dB at 38 ​GHz. The proposed switches which are optimized at 41 ​GHz does not contains the perforations and suffers from serious stiction problems at downstate. Hence, perforations are introduced in switch membrane and fabricated using surface micromachining technology. The optimized iterative meander switch shows low pull – in voltage of 1.85 ​V which is closely approximated to the simulated value.

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 simulation of a RF MEMS shunt capacitive switch with low actuation voltage, low loss and high isolation

Design and simulation of a RF MEMS shunt capacitive switch with low actuation voltage, low loss and high isolation

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 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.

Design and simulation of RF MEMS switch for use in the millimetre wavelength range and SPDT RF MEMS switch

This article describes in detail the design of a shunt capacitive RF MEMS switch for Ka-frequency band, as well as the design of a single-pole-double-directional RF MEMS switch made on its basis. An electrostatic and electromagnetic analysis was performed using the MATLAB and ANSYS HFSS software package. The switch uses a 1.52 V actuation voltage and 1.3 μs of switching time to move the membrane from the up state to the down state. The operating frequency range of this switch is between 24-34 GHz with isolation of -53 dB at 29 GHz and reflection loss of -0.25 dB for this frequency range. The design of the switch is made on a GaAs substrate with a thickness of 525 μm with a double-sided insulating layer of silicon oxide with a thickness of 2 μm.

Design and analysis of enhanced capacitive radio frequency MEMS switch based on Nb2O5 and HfO2 dielectric for satellite payload applications

AbstractAn innovative capacitive radio frequency MEMS shunt switch with a unique shaped spring is designed and analyzed using COMSOL Multiphysics 5.4. The proposed switch using Hafnium oxide (HfO2) and Niobium pentoxide (Nb2O5) as the dielectric material between the transmission line and the deflecting gold membrane provides certain advantageous benefits with respect to performance parameters such as low actuation voltage, less spring constant, good isolation, low insertion loss, small size, and high capacitance ratio compared to other designs. A combination of three‐turn meander and C‐ shaped spring having a spring constant of 0.186 N/m helps in achieving convenient actuation voltage. For 1, 1.5, and 2 μm air gaps, the actuation voltages required to bring the switch to ON mode are 1.77, 3.24, and 4.96 V respectively with Nb2O5 as the dielectric layer and 1.8, 3.28, and 5.01 V respectively with HfO2 as the dielectric layer respectively. At 2‐μm air gap, the capacitance ratio is 329 for Nb2O5 and 113 for HfO2. RF analysis using ANSYS HFSS software shows the isolation of −19.41 dB at 11 GHz and insertion loss as low as −0.27 dB at 15 GHz. The proposed switch operating within the range of 1 to 30 GHz gives optimum results compared to other devices and is suitable for wireless communication and satellite payload applications.

Design of Step down Structure RF-MEMS Shunt Capacitive Switch for Low-Pull-In Voltage

In this paper, designs and simulations of a new RF MEMS step-down structure of a capacitive shunt switch using different meandering methods are presented. The beam and dielectric materials are taken as gold and silicon nitride for the proposed switch. The switch required actuation voltage is 7.9 V for the non-uniform one meander technique.

Design, and Analysis of Capacitive Shunt RF MEMS Switch for Reconfigurable Antenna

This paper presents design and the performance analysis of capacitive shunt RF MEMS Switch. Here, the proposed Rf MEMS Switch shows the low pull-in voltage i.e 11.97 V and performed at 38 GHz with high isolation. To improve the performance of antenna characteristics microstrip feeding technique and co-planar-waveguide transmission line feeding are used in this design process. The impedance matching of 50Ω in the antenna is depends on the width of the feed line can be observed through simulated smith chart by using the Ansoft HFSS simulator. The micro strip patch antenna exhibits a Return loss is − 12.4264 dB and exhibits resonance at 38 GHz and the band width frequency from 37 to 39 GHz.After analyzing the performance of the antenna then the antenna is integrated with RF MEMS capacitive shunt switch through co-planar wave guide transmission feedline technique. By integrating with switch there is a frequency shift OF 1 GHz toward right from 38 GHz in antenna. The resonance is occurred at 39 GHz with bandwidth frequency between 38 and 40 GHz. The antenna exhibits return loss is − 27.2666 dB at operating frequency 39 GHz with RF MEMS switch and total gain of the antenna at 38 GHz with angle of ϕ = 90° is 5.6671 dB. Thus the performance of the antenna is increased by integrating with RF MEMS switch. These type of reconfigurable antennas are used in high frequency applications at frequency range of Ka-band and in wireless communication applications and satellite communication.

Development of a low stress RF MEMS double-cantilever shunt capacitive switch

In this paper, a novel RF MEMS shunt capacitive switch with application in the Ka frequency band is proposed. The spring design and the step structure added to the beam succeeded in improving the performance of the switch and reducing the stress which results in extended life-time of the switch. Also, by optimally reducing the gap between the dielectric and the beam (without problems such as self-actuation), the actuation voltage of the switch is significantly reduced. Electromechanical and scattering parameters analysis have been done by using COMSOL Multiphysics and HFSS software, respectively. The actuation voltage of the proposed device is 9.2 V. Since the aluminum has a lower mass compared to gold, an aluminum beam has been used in the switch. Desirable scattering parameters at the resonance frequency of 33.5 GHz have been obtained which include insertion loss of − 0.3 dB and return loss of − 18 dB. The high isolation of − 57 dB verifies the improved performance of the switch. Finally, as another innovation in this paper, the effect of inductor and capacitor presence in the input of transmission line is investigated. This analysis has been done by using ADS. Results of the circuit analysis presented in this paper, help the MEMS switch designers to understand the realistic switch behavior before fabrication which considerably saves cost and time.