ebrahim Abbaspour - Academia.edu (original) (raw)

Papers by ebrahim Abbaspour

Inthis paperwestudied theeffect ofresidual stress on pull-In voltage offixed-fixed endtypeMEM swi... more Inthis paperwestudied theeffect ofresidual stress on pull-In voltage offixed-fixed endtypeMEM switches with variative electrostatic area. We usedthedistributed modelwhen theelectrostatic pressure didn't applyatthewholeofthebeam andapplied onlyinthemid-part ofthebeam.Themodeluses Euler-Bernoulli beamtheory forfixed-fixed endtypebeamswith respect toresidual stress duetofabrication process. Thederived nonlinear equation hasbeensolved numerically, andhasshown thattheresidual stress changes thePull-In voltage offixed-fixed endtypeMEM switches withvariative electrostatic area. Keywords-Electrostatic pressure; MEMS; Pull-in voltage; Residual Stress; Varying Section.

2006 1st IEEE International Conference on Nano/Micro Engineered and Molecular Systems, 2006

Abstract In this paper we studied the effect of residual stress on pull-In voltage of fixed-fixed... more Abstract In this paper we studied the effect of residual stress on pull-In voltage of fixed-fixed end type MEM switches with variative electrostatic area. We used the distributed model when the electrostatic pressure didn&amp;#x27;t apply at the whole of the beam and applied only in the ...

Two high-Q micromachined electro-mechanically tunable capacitors are presented. The proposed desi... more Two high-Q micromachined electro-mechanically tunable capacitors are presented. The proposed designs are CMOS-compatible that can be integrated with CMOS circuit in a single die. In these structures there is no need for cantilever beams which introduce considerable series resistance to the capacitor and decrease the quality factor. So our proposed structures achieve better Q in a smaller area. The simulated 1pF full plate capacitor with aluminium deposition on top plate shows a tuning range of 42% and a Q of 47 at 1 GHz. For the comb structure the tuning range is 43% and Q is 45 at 1 GHz. Pull-in voltage is 3.5 V for both capacitors. The S11 responses are reported for a frequency range from 1 up to 4 GHz.

EuroSimE 2005. Proceedings of the 6th International Conference on Thermal, Mechanial and Multi-Physics Simulation and Experiments in Micro-Electronics and Micro-Systems, 2005.

A high-Q micromachined electro-mechanically tunable capacitor for RF application is presented. Th... more A high-Q micromachined electro-mechanically tunable capacitor for RF application is presented. The proposed design is CMOS-compatible that can be integrated monolithically with CMOS circuit in a single die. In this structure there is no need for cantilever beams which introduce considerable series resistance to the capacitor and decrease the quality factor. So our varactor achieve better Q in a smaller

Progress In Electromagnetics Research, 2007

Two novel structures for high-Q MEMS tumble capacitors are presented. The proposed designs includ... more Two novel structures for high-Q MEMS tumble capacitors are presented. The proposed designs include full plate as well as the comb structured capacitors. They can be fabricated employing surface micromachining technology which is CMOS-compatible. The structures do not require the cantilever beams which introduce considerable series resistance to the capacitor and decrease the quality factor. Therefore, our proposed structures achieve better Q in a smaller die area. The simulated results for 1 pF full plate capacitor shows a tuning range of 42% and a Q of 47 at 1 GHz. However, with the same initial capacitance, but the comb structure, the tuning range is increased to 43% but the Q is decreased to 45 at 1 GHz. The simulated Pull-in voltage with no residual stress is 3.5 V for both capacitors. The S 11 responses are reported for a frequency range from 1 up to 4 GHz.

A novel structure with electro-mechanically tunable capacitor for RF application is presented. Th... more A novel structure with electro-mechanically tunable capacitor for RF application is presented. The suspended electrodes are designed in such a way that both are electrostaticaly displaceable. This double plate moveability feature of the capacitor increases the tuning range. In this structure, there is no need for cantilever beams, which introduce considerable series resistance to the capacitor and decrease the quality factor. Therefore, our proposed varactor achieves better Q in a smaller area. The simulated one pF capacitor shows a Q of 40 at 1 GHz and a tuning range of 42%. Pull-in voltage is 3.6 V, which is a reasonable value for submicron CMOS technologies.

ICONIP '02. Proceedings of the 9th International Conference on Neural Information Processing. Computational Intelligence for the E-Age (IEEE Cat. No.02EX575)

... E.Abbaspour-Sad, Advisor, SAfrang', IEEE Student Member, MMTeymoori3, IEEE Student Membe... more ... E.Abbaspour-Sad, Advisor, SAfrang', IEEE Student Member, MMTeymoori3, IEEE Student Member Department of Electrical Engineering Urmia MEMS Lab Urmia University AMRC (Advanced Manufacturing Research Center), Unnia, IRAN 'e.abbasoour@mail.unnia.ac.ir ...

IEEE International Conference on Semiconductor Electronics, 2002

A novel capacitive pressure sensor based on surface micromachining technology is designed and sim... more A novel capacitive pressure sensor based on surface micromachining technology is designed and simulated. The sense element is a parallel plate capacitor with one electrode fixed to the substrate, and the other suspended on a polysilicon diaphragm. In the presence of an oil pressure, the silicon diaphragm is deflected downward, which also displaces the suspended electrode downward. The sensor structure

Sensors and Actuators A: Physical, 2005

... Urmia MEMS Lab, Department of Electrical Engineering, Urmia University, Beheshti Ave., Urmia ... more ... Urmia MEMS Lab, Department of Electrical Engineering, Urmia University, Beheshti Ave., Urmia 57135, Iran. Received 20 January 2004; revised 19 June 2004; accepted 21 June 2004. Available online 13 August 2004. Abstract. ...

Microsystem Technologies, 2010

Design and simulations of a novel RF MEMS switch is reported as a solution to many RF wireless ap... more Design and simulations of a novel RF MEMS switch is reported as a solution to many RF wireless applications. A new comb structure for RF MEMS switch is proposed for low voltage and high frequency operations. Isolation degree and actuation voltage, both improved by the new structure. The mechanical and electromagnetic simulation results show better performance for this new switch compared to parallel plate switch. The simulation is done by the intellisuit and HFSS softwares. The Simulation results show that the actuation voltage is decreased by 13% and the linearity of the switch displacement with respect to the actuation voltage is improved by 22% compared to the parallel plate structure. The HFSS simulation results indicate an insertion loss better than 0.33 dB at 50 GHz and isolation greater than 13.4 dB at 50 GHz.

Journal of Physics: Condensed Matter, 2008

ABSTRACT The effects of oxygen gas pressure and operating temperature on the sensing layer of res... more ABSTRACT The effects of oxygen gas pressure and operating temperature on the sensing layer of resistive oxygen gas sensors are analytically studied. We include the effects of the temperature, gas pressure, energy gap, Fermi energy, and concentration of the electrons and holes. To achieve more accurate equations for the temperature and gas pressure dependency of the oxide semiconductor sensing layers, Fermi–Dirac distribution is employed instead of the conventionally used Boltzman function. Consequently, we have derived new equations that give the variation of conductivity of the sensing layer as a function of operating temperature and gas pressure more accurately. To examine the exactness of our derived equations, the responses of CeO2 and SrTi0.65Fe0.35O3−δ based oxygen gas sensors as a function of temperature and gas pressure are calculated using Matlab software. The obtained results are in close agreement with the reported measured results.

Journal of Physics: Conference Series, 2006

... Fixed-Fixed End Type MEMS Switches Hamed Sadeghian Mech. Eng. Dept., Urmia university,Urmia, ... more ... Fixed-Fixed End Type MEMS Switches Hamed Sadeghian Mech. Eng. Dept., Urmia university,Urmia, Iran, Sadeghian7@yahoo.com Ghader Rezazadeh Mech. Eng. Dept., Urmia university,Urmia, Iran G.Rezazadeh@mail.urmia.ac.ir Ebrahim Abbaspour Sani Elec.Eng. ...

Progress In Electromagnetics Research, 2006

A novel structure for the capacitive micromachined switches with low actuation voltage is propose... more A novel structure for the capacitive micromachined switches with low actuation voltage is proposed. In this structure both contact plates of the switch are designed as displaceable membranes. Two structures with similar dimensions and conditions, differing on only the number of the displaceable beams are analytically investigated as well as simulated using ANSYS software. The obtained results indicate about 30% reduction in actuation voltage from the conventional single beam to our proposed double beam structure. The stress on the beam due to the actuation voltage is also reduced increasing the switching life time. The dynamic simulation results in switching time of 6.5 µsec compared to the 8.9 µsec of the analytical results. It can be implemented by the well established surface micromachining for RF applications.