Showing 3 results for Rf Mems Switch
S. Delaram Farimani, H. Hajghasem, A. R. Erfanian, M. R. Aliahmad,
Volume 12, Issue 2 (10-2015)
Abstract
In this paper, design, analysis and fabrication of a low loss capacitive RF MEMS shunt switch, which made on the coplanar waveguide transmission line and alumina substrate in the frequency band of 40-60 GHz, is presented. The CPW is designed to have 50Ω impedance matching on the alumina substrate. Then the desired switch is designed with appropriate dimensions. Afterward the important parameters are obtained by finite element and full-wave electromagnetic simulations by CoventorWare and HFSS. It is shown that for the designed switch, pull-in voltage is 19.25v, insertion-loss is 0.8dB, return-loss is more than 9.8dB and the isolation is 50dB. At the end, the laboratory sample of designed switch is fabricated on alumina substrate and tested, and the possible parameters are obtained. We concluded that the designed switch has appropriate insertion and return loss and good isolation, and fabricated switch has acceptable properties.
Hamid Reza Ansari, Dr. Saeed Khosroabadi, Dr. Yasser Mafinejad,
Volume 18, Issue 1 (3-2021)
Abstract
According to contact type, RF MEMS switches are generally classified into two categories: Capacitive switches and Metal-to-Metal ones. The capacitive switches are capable to tolerate a higher frequency range and more power than M-to-M switches. This paper presents a cantilever shunt capacitive RF MEMS switch with characteristics such as low trigger voltage, high capacitive ratio, short switching time and high isolation. In this switch, aluminum bridge is used because of its high Young’s modulus and low density which help reduction of switching time. Also aluminum has a good electrical conductivity which increases isolation. The proposed switch is designed on a Coplanar Waveguide line (CPW) with impedance of 50Ω. Also, is used as dielectric layer. 24 holes have been placed on the bridge surface to reduce the squeeze film damping and to increase the switching speed. Actuation voltage is 5.2v and capacitive ratio (CR) is 231. RF analysis is done in HFSS Software. The results show the isolation level as -27dB, insertion loss as -0.2dB and return loss as -22dB at 17GHz. Also, the switching time is 32us.
Farid Khamoii Toli, Dr. Javad Yavand Hasani,
Volume 19, Issue 2 (4-2022)
Abstract
High actuation voltage is one of the most important limitations of RF MEMS switches. One way to reduce the actuation voltage is to reduce the spring constant in the switch structure. In this paper, we model the spring constant using Energy Model and we obtain an analytic equation to calculate it. The result is an analytic design guide that determines the minimum value of the spring constant. Then, a new RF MEMS structure with very low actuation voltage is presented. The structure is modeled by the energy method and the spring constant is calculated analytically. Analysis results show the spring constant of 0.0714 N/m and an actuation voltage of 1.61 V. To evaluate the performance of the proposed structure and to validate the results of the analysis, a switch was designed using simulated COMSOL software. The results of this simulation show the actuation voltage of 1.8 volts, the switching time of 25.6 microseconds, the 4.5 MPa Von Mises stress, the natural frequency of 3118.6 Hz, its mass of 0.206 ng and finally the spring constant of 0.079 N/m. The beam is made of gold and Si3N4 is used as a dielectric. Finally, the high frequency performance of the switch is designed using simulated HFSS software. The simulation shows a 25 dB isolation, a 0.7 dB insertion loss, and a 16 dB return loss at 10 GHz.
