Design and Analysis of Serpentine Flexure Based RF MEMS Switch for High Isolation with Low Pull-in voltage

K. Girija Sravani,Koushik Guha,K. Srinivasa Rao 한국전기전자재료학회 2019 Transactions on Electrical and Electronic Material Vol.20 No.2

This paper presents the design and performance analysis of radio frequency micro electro mechanical system switches having serpentine fl exure designs. In this paper, we have done, behavioral analysis by changing material, gap and thickness, increase in the actuation area using menders, impact of holes on eff ective working of the switch, stress analysis for low spring constant, electromechanical analysis for low pull-in voltage and high capacitance ratio, time dependent analysis for faster switching time, scattering parameter analysis for reducing RF losses are simulated and compared with the theoretical analysis. The signifi cant improvements in this work are lesser air gap and beam thickness reduced the pull-in voltage to 2.75 V for 1.66 μm displacement, a rapid switching time of 0.9 μs obtained through simulation, an improved capacitance ratio of 157.25, isolation is 49.59 dB, insertion loss is 0.005 dB. Actuation area is increased, and switch area is reduced to achieve the optimum performance of the switch.

Analysis on Selection of Beam Material for Novel Step Structured RF-MEMS Switch used for Satellite Communication Applications

K. Girija Sravani,Koushik Guha,K. Srinivasa Rao 한국전기전자재료학회 2018 Transactions on Electrical and Electronic Material Vol.19 No.6

This paper mainly reports a proper selection of beam material for the step structured based RF MEMS switch. Generally,the performance of the device purely depends upon beam material used for the RF switch. There is a wide range of materialsavailable for the beam layer which may change the performance of RF switch with their distinct material properties. Thoughvarious material selection methods are implemented earlier, among those methodologies Ashby’s material approach requiresminimum execution steps for the beam selection based on various geometrical and performance indices. There are mainlythree key performance indices like actuation voltage, S-parameters and residual stress by heat, are used to obtain the desiredperformance. The material selection in this work says that SU-8, PTFE followed by aluminum and gold are the more suitablematerials for beam material selection for Step structured RF-MEMS switch. Due to fabrication complexity, SU-8 andPTFE are not considered for the beam layer. After the investigation, the above given two material (i.e.) Gold and Aluminumare preferable for the beam, owing to its high cost gold is not much preferable material for the beam. Therefore, Aluminumis good for the beam layer.

Design of a Non-uniform Serpentine Asymmetric Cantilever RF-MEMS Shunt Capacitive Switch for RADAR Applications

Ch. Gopichand,Reshmi Maity,N. P. Maity,K. Srinivasa Rao,Koushik Guha,Santanu Maity,Ameen Eisnawi 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.4

This paper presents the design and simulation of Cantilever type RF-MEMS Capacitive shunt switch with meanders and perforations. The main objective of this paper is to reduce the pull-in voltage and increases isolation of the proposed switch. Electro-mechanics and Solid-mechanics are used to simulate the proposed switch by using COMSOL Multiphysics software. The capacitance, switching time, stress analysis are calculated and compare both theoretical and simulation results of the proposed switch. By varying diff erent beam thickness, materials, an air gap between the beam and signal line to calculate spring constant and pull-in voltage. The proposed switch having pull-in voltage is 1.371 V, the dielectric material Si 3 N 4 is to improve the capacitance analysis of the switch. The up and downstate capacitance is 7.073 fF, 1.259 pF. The RF performance is simulated by using Ansoft HFSS tool, the switch performs at low frequencies at 1–4 GHz range. The return (S 11 ) and insertion loss (S 12 ) of the proposed switch is − 30 dB, − 0.0516 dB and the switch having good isolation (S 21 ) is − 37.5 dB at 1.5 GHz frequency. The switch is suitable for radar and satellite communication applications.

Target Application Based Design Approach for RF MEMS Switches using Artificial Neural Networks

Lakshmi Narayana Thalluri,Samuyelu Bommu,Sathuluri Mallikharjuna Rao,K. Srinivasa Rao,Koushik Guha,S. S. Kiran 한국전기전자재료학회 2022 Transactions on Electrical and Electronic Material Vol.23 No.5

In this paper, a target application-based design approach for RF MEMS switches using artifi cial neural networks (ANN) is presented. ANN approach is used to decide the dimensions of the RF MEMS switch for the targeted application. The ANN approach design and analysis is done using MATLAB. The results obtained by ANN method are validated using the FEM tool simulation, which show that the developed models have good accuracy over the range of switch dimension values for the intended application. The switch dimensions are extracted for L, S, C, X, Ku, K, and Ka-band applications using ANN. Eventually, a novel RF MEMS switch based on the ANN approach for C-band applications is proposed. The required pullin voltage will increase because of perforation, and this problem is handled by adding extra weight to the membrane with pillars and slabs. Analyzed load distribution in membrane with perforation. FEM design is implemented using solid mechanics and electrostatic-based Multi-physics in COMSOL environment. Diff erent studies, i.e., stationary, time-dependent, and frequency domain are performed to extract electrical, mechanical, and Radio Frequency parameters of the proposed design. The switch designed for C-band applications off ering an actuation voltage of 7.4 V, Insertion loss of − 0.2 dB, and Isolationloss of − 57 dB.

Jacobian Based Nonlinear Algorithms for Prediction of Optimized RF MEMS Switch Dimensions

Lakshmi Narayana Thalluri,M Aravind Kumar,Mohamed Sultan Mohamed Ali,N. Britto Martin Paul,K. Srinivasa Rao,Koushik Guha,S. S. Kiran 한국전기전자재료학회 2023 Transactions on Electrical and Electronic Material Vol.24 No.5

This communication discusses the role of nonlinear algorithms in training the neural network, which predicts the optimized RF MEMS switch dimensions. A dedicated dataset, i.e., DrTLN-RF-MEMS-SWITCH-DATASET-v1, was created by considering the most appropriate input and output variable suitable to predict the cantilever dimensions, crab leg and serpentine structure-based RF MEMS switches. The distinct artificial neural networks (ANN) performance is analysed using various training methods. The hardware implementation possible neural network algorithms, i.e., Fitting and Cascade Feed Forward Network, are considered for learning and prediction. The ANN algorithm's performance in predicting and optimizing RF MEMS switch is analysed using nonlinear training methods like Levenberg–Marquardt (LM) and Scaled Conjugate Gradient (SCG). The cascaded forward network with LM training combination offers the best performance compared with other varieties. A comprehensive study is performed using neural networks and finite element simulation results. The study revealed that the error percentage is below 15.08% for most of the parameters.

Low Pull-in-Voltage RF-MEMS Shunt Switch for 5G Millimeter Wave Applications

P. Ashok Kumar,K. Srinivasa Rao,B. Balaji,M. Aditya,N. P. Maity,Reshmi Maity,Santanu Maity,Ameen El Sinawi,Koushik Guha,K. Girija Sravani 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.6

RF MEMS switches have been employed in many commercial and defense applications due to their high potentiality at microwave and millimeter wave frequencies. In this paper, an RF MEMS shunt switch is designed with perforations and without perforations and simulated using iterative meanders for millimeter wave 5G applications. The proposed iterative meander offers a low spring-constant of 0.68 N/m and reduces the pull-in-voltage upto 1.8 V. The proposed perforated switch design is more reliable which operates with less transition time of 11.2 μs with a quality factor of 1.69. The switch possesses high capacitance ratio of 63. During ON condition, the switch shows low insertion loss of − 0.24 dB at 41 GHz and high isolation of − 46.7 dB at 38 GHz. The performance of the switch is analyzed by simulating it using COMSOL Multiphysics 5.2v (FEM tool). The obtained simulation results shows close approximation with the theoretical results and the switch is efficiently used for 5G millimeter wave applications.

Smart City IoT System Network Level Routing Analysis and Blockchain Security Based Implementation

Bommu Samuyelu,M Aravind Kumar,Babburu Kiranmai,N Srikanth,Thalluri Lakshmi Narayana,G V. Ganesh,Gopalan Anitha,Mallapati Purna Kishore,Guha Koushik,Mohammad Hayath Rajvee,S S. Kiran 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.2

This paper demonstrates, network-level performance analysis and implementation of smart city Internet of Things (IoT) system with Infrastructure as a Service (IaaS) level cloud computing architecture. The smart city IoT network topology performance is analyzed at the simulation level using the NS3 simulator by extracting most of the performance-deciding parameters. The performance-enhanced smart city topology is practically implemented in IaaS level architecture. The intended smart city IoT system can monitor the principal parameters like video surveillance with a thermal camera (to identify the virus-like COVID-19 infected people), transport, water quality, solar radiation, sound pollution, air quality (O3, NO2, CO, Particles), parking zones, iconic places, E-suggestions, PRO information over low power wide area network in 61.88 km × 61.88 km range. Primarily we have addressed the IoT network-level routing and quality of service (QoS) challenges and implementation level security challenges. The simulation level network topology analysis is performed to improve the routing and QoS. Blockchain technology-based decentralization is adopted to enrich the IoT system performance in terms of security.