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Microsystem Technologies

, Volume 25, Issue 2, pp 531–540 | Cite as

Design and simulation of a novel RF MEMS shunt capacitive switch with a unique spring for Ka-band application

  • Hamid Reza AnsariEmail author
  • Saeed Khosroabadi
Technical Paper
  • 112 Downloads

Abstract

RF-MEMS switches may be divided into capacitive and metal-to-metal types in terms of type of connection. In capacitive switches in the OFF-state the beam does not attach to the transmission line due to the presence of a thin dielectric layer and it gets released easily. Capacitive switches are better compared with the metal-to-metal types due to their ability to transmit signals of higher frequency and power. In this paper, a novel RF MEMS shunt capacitive switch with a unique spring design is proposed. The proposed design benefits from high isolation, low loss, low actuation voltage, small size and weight compared to similar switches and is designed for application in the Ka-band. Step structure is used in the mechanical design of the switch to reduce the air gap between the bridge and the transmission line that has resulted in reduction of actuation voltage to 2.2 V. The proposed switch has been placed upon a coplanar waveguide (CPW) line with an impedance of 50 Ohms. \({\text{SiO}}_{2}\) with a thickness of 1000 Å has been used as dielectric to increase isolation and down-state capacitance. The unique design of the spring results in the reduction of stress to a minimum at all points of the switch especially the springs at the time of applying the actuation voltage. This advantage would reduce switch failures as time passes and results in increased life of the switch. Up-state capacitance is 93.3 fF and down-state capacitance is 2.64 pF. Therefore, a capacitive ratio of 28 is obtained. The dynamic behavior of the switch is studied by using the COMSOL Multiphysics software package and the RF characteristics have been obtained by using the HFSS software and show good RF performance. The results show that in the up-state, the designed switch including S11 is less than − 11.5 dB and S21 is more than − 0.85 dB at 1–40 GHz. In the down-state, the switch has excellent isolation in the Ka-band. Maximum isolation is − 71 dB that occurs at the resonance frequency of 30.5 GHz.

Notes

References

  1. Deng Z, Wei H, Fan S, Gan J (2015) Design and analysis a novel RF MEMS switched capacitor for low pull—in voltage application. Microsyst Technol 22:2141–2149.  https://doi.org/10.1007/s00542-015-2604-6 CrossRefGoogle Scholar
  2. Girija Sravani K, Srinivasa Rao K (2018) Analysis of RF MEMS shunt capacitive switch with uniform and non-uniform meanders. Microsyst Technol 24:1309–1315.  https://doi.org/10.1007/s00542-017-3507-5 CrossRefGoogle Scholar
  3. Khodadady K, Azizolla B (2015) Design and modeling of a novel RF MEMS series switch with low actuation voltage. Microsyst Technol.  https://doi.org/10.1007/s00542-015-2683-4 Google Scholar
  4. Lee J, Yang WS, Kang S, Choi CA (2004) Design and parameterextraction based small-singal modeling of a novel centeranchor MEMS series switch. In proceedings of the 34th European Microwave Conference. Amsterdam, The Netherlands, pp 1433–1436Google Scholar
  5. Ma LY, Nordin AN, Soin N (2018) A novel design of a low-voltage low-loss T-match RF-MEMS capacitive switch. Microsyst Technol 24:561–574.  https://doi.org/10.1007/s00542-017-3577-4 CrossRefGoogle Scholar
  6. Mafinejad Y, Kouzani A, Mafinezhad K, Hosseinnezhad R (2017) Low insertion loss and high isolation capacitive RF MEMS switch with low pull-in voltage. Int J Adv Manuf Tech 93:661–670.  https://doi.org/10.1007/s00170-017-0558-9 CrossRefGoogle Scholar
  7. Molaei S, Ganji BA (2017) Design and simulation of a novel RF MEMS shunt capacitive switch with low actuation voltage and high isolation. Microsyst Technol 23:1907–1912.  https://doi.org/10.1007/s00542-016-2923-2 CrossRefGoogle Scholar
  8. Ravirala AK, Bethapudi LK, Kommareddy J et al (2018) Design and performance analysis of uniform meander structured RF MEMS capacitive shunt switch along with perforations. Microsyst Technol 24:901–908.  https://doi.org/10.1007/s00542-017-3403-z CrossRefGoogle Scholar
  9. Rebeiz GM (2003) RF MEMS: theory, design and technology. Wiley, New JerseyCrossRefGoogle Scholar
  10. Shekhar S, Vinoy KJ, Ananthasuresh GK (2017) Surface-micromachined capacitive RF switches with low actuation voltage and steady contact. J Microelectromech Syst 26:643–652.  https://doi.org/10.1109/JMEMS.2017.2688519 CrossRefGoogle Scholar
  11. Yu HW, Kim J (2015) Low-voltage micromechanical RF switch based on a piezoelectric micro-cantilever integrated with a transmission line. J Korean Phys Soc 67:1942–1946.  https://doi.org/10.3938/jkps.67.1942 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Electrical Engineering DepartmentImam Reza International UniversityMashhadIran

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