Fabrication and analysis of radiofrequency MEMS series capacitive single-pole double-throw switch
06 Oct 2016-Journal of Micro-nanolithography Mems and Moems (International Society for Optics and Photonics)-Vol. 15, Iss: 4, pp 045001-045001
TL;DR: In this paper, a single-pole double-throw (SPDT) switch based on series capacitive configuration is proposed, and the critical process parameters are analyzed to improve the fabrication process.
Abstract: A compact radiofrequency (RF) MEMS single-pole double-throw (SPDT) switch based on series capacitive configuration is proposed. The critical process parameters are analyzed to improve the fabrication process. A technique of cold–hot thermal shock for lift-off method is explored. The residual stress in the structure is quantified by lancet test structures that come out to be 51 MPa. Effect of residual stress on actuation voltage is explored, which changes its value from 24 to 22 V. Resonance frequency and switching speed of the switch are 11 kHz and 44 μs, respectively, measured using laser Doppler vibrometer. Measured bandwidth of the SPDT switch is 20 GHz (5 to 25 GHz), which is verified with finite element method simulations in high frequency structure simulator© and an equivalent LCR circuit in advanced design system©. Insertion loss of the switch lies in −0.1 to −0.5 dB with isolation better than −20 dB for the above-mentioned bandwidth.
Citations
More filters
TL;DR: In this article, a single pole single throw (SPST) switch is developed without using any additional step, and the measured switching time of the switch is $1.8~\mu \text{s}$.
Abstract: RF MEMS ohmic switches are prone to stiction and contact degradation. In literature, bumps are made at the contact area to reduce stiction with additional fabrication steps. In this article, ohmic switch based on cantilever configuration is developed without using any additional step. The switch structure is modified to improve its mechanical parameters, such as pull-in voltage and switching speed. The measured switching time of the switch is $1.8~\mu \text{s}$ . A footprint of the developed single pole single throw (SPST) switch is 0.9 mm2. The insertion loss and isolation of the SPST switch are better than 0.8 and 20 dB, respectively. The switch has a wide bandwidth of 10 GHz (dc to 10 GHz). The switch has completed 725 million hot cycles at 1-dBm power.
13 citations
13 Feb 2019-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this article, a hybrid technique is used for the designing of a compact, high isolation and the enhanced bandwidth SPDT RF MEMS switch for 5G applications, which offers greater than 40dB isolation over a wide frequency range (>40dB over 22.10 GHz bandwidth) with less than 0.30dB insertion loss over the entire band.
Abstract: Fifth generation (5G) communication system enables the pathway for a higher data transfer rate. The frequency bands used for 5G communication system are distributed from lower frequency range (600 MHz) to a higher frequency range (60 GHz). So it is necessary that a single switch should be able to cover the complete range of 5G frequency bands. The ohmic radio frequency-micro electromechanical system (RF-MEMS) switch has offered high isolation at lower frequencies (> 40 dB up to 2.5 GHz). However, 5G requires a higher frequency range which is covered by capacitive switch. The capacitive switch has limitations of limited bandwidth and large size. In this paper, a hybrid technique is used for the designing of a compact, high isolation and the enhanced bandwidth SPDT RF MEMS switch for 5G applications. The size of the proposed switch is half from the conventional capacitive RF MEMS switch and offer greater than 40 dB isolation over a wide frequency range (> 40 dB over 22.10 GHz bandwidth) with less than 0.30 dB insertion loss over the entire band.
5 citations
01 Sep 2018-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this paper, a mixed release process of wet and dry is presented to release the stiction free suspended microstructures, which is removed by plasma cleaning, which improves the isolation of the device under test to 22 dB from 15 dB after plasma exposure.
Abstract: RF MEMS switches have moving microstructures which are realized either by dry release method or by wet releasing process. In dry release process, suspended bridges gets curled up due to high process temperature while in wet release method, surface of the released devices is get contaminated which affects the final performance of the device. In this paper, a mixed release process of wet and dry is presented to release the stiction free suspended microstructures. Contamination from the devices is removed by plasma cleaning. Isolation of the device under test has been improved to 22 from 15 dB after plasma exposure.
4 citations
TL;DR: In this article, the authors extracted the RF MEMS capacitive switch LCR parameters considering parasitic capacitance to explain the mismatch of measured results, which is a function of switch geometry and directly proportional to dielectric constant of the substrate material.
Abstract: Radio frequency micro-electro-mechanical system (RF MEMS) switch is basic component for transponders used in communication system. Switch “OFF/ON” capacitance ratio plays major role in controlling signal to noise ratio. Theoretically, with high dielectric constant material or floating metal concept, capacitance ratio can be improved up to 2000 or even more. Whereas, in most of the practical cases, measured ratio is less than 200. In present paper, RF MEMS capacitive switch LCR parameters are extracted considering parasitic capacitance to explain the mismatch of measured results. Parasitic capacitance is independent from device overlap area. Parasitic capacitance is function of switch geometry and directly proportional to dielectric constant of the substrate material.
4 citations
01 Aug 2019-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this paper, inverted silicon cavity is used for capping the MEMS devices and the electrical and mechanical characteristics of the RF MEMS switch are analyzed using finite element method simulations.
Abstract: Packaging is one of the most critical tasks for MEMS devices. Unlike solid state devices, MEMS structures involves moving structures which needs to be protected from outer environment ensuring free movement of the structure. In the present paper, inverted silicon cavity is used for capping the MEMS devices. However, in case of RF MEMS, silicon cavity would add parasitics and affects its electrical performance. Enclosing the MEMS structure, its mechanical response will also alter. The electrical as well as mechanical characteristics of the RF MEMS switch are analyzed using finite element method simulations. The electrical response of the fabricated switch after packaging is compared with unpackaged device.
2 citations
References
More filters
TL;DR: In this paper, a two-pole filter is proposed based on capacitively loaded folded-λ/2 resonators coupled to a microstrip line, and the filter analysis includes the effects of nonadjacent inter-resonator coupling.
Abstract: This paper presents a compact low-loss tunable X-band bandstop filter implemented on a quartz substrate using both miniature RF microelectromechanical systems (RF-MEMS) capacitive switches and GaAs varactors. The two-pole filter is based on capacitively loaded folded-λ/2 resonators that are coupled to a microstrip line, and the filter analysis includes the effects of nonadjacent inter-resonator coupling. The RF-MEMS filter tunes from 11.34 to 8.92 GHz with a - 20-dB rejection bandwidth of 1.18%-3.51% and a filter quality factor of 60-135. The GaAs varactor loaded filter tunes from 9.56 to 8.66 GHz with a - 20-dB bandwidth of 1.65%-2% and a filter quality factor of 55-90. Nonlinear measurements at the filter null with Δf = 1 MHz show that the RF-MEMS loaded filter results in > 25-dBm higher third-order intermodulation intercept point and P-1 dB compared with the varactor loaded filter. Both filters show high rejection levels ( > 24 dB) and low passband insertion loss ( <; 0.8 dB) from dc to the first spurious response at 19.5 GHz. The filter topology can be extended to higher order designs with an even number of poles.
97 citations
"Fabrication and analysis of radiofr..." refers background in this paper
...Evolution of miniaturized wireless communications and lowpower requirements have shifted research trends from power hungry solid-state devices to RF MEMS devices, such as switches, antennae,(6) and filters.(7,8) Electrical response such as power handling, isolation, and insertion loss of RF MEMS switches are better than solid-state counterparts, but applications in the real world are limited owing to their reliability issues....
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01 Feb 2014-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this article, a novel torsional RF MEMS capacitive switch design on silicon substrate is presented, which optimized switch topology such as reduction in up-state capacitance results in insertion loss better than 0.1 dB till 20 GHz.
Abstract: A novel torsional RF MEMS capacitive switch design on silicon substrate is presented. The optimized switch topology such as reduction in up-state capacitance results in insertion loss better than ź0.1 dB till 20 GHz. Off to on state capacitance ratio is also improved by 18 fold and isolation is better than ź43 dB at 9.5 GHz. The achieved on state return loss is ź38 dB as compared to ź21 dB at 9.5 GHz. An optimized reduction in contact area and use of floating metal layer increases the switching speed from 56 to 46 μsec. It also increases the switch reliability by alleviating the stiction.
56 citations
TL;DR: In this paper, a 20-GHz radio frequency microelectromechanical system (RF MEMS)-based electrically switchable antenna on a quartz substrate was demonstrated with a single-pole double-throw (SPDT) switch router network on a 21 mm times 8 mm chip.
Abstract: This letter demonstrates a 20-GHz radio frequency microelectromechanical system (RF MEMS)-based electrically switchable antenna on a quartz substrate Two quasi-Yagi antenna elements are monolithically integrated with a single-pole double-throw (SPDT) MEMS switch router network on a 21 mm times 8 mm chip Electrical beam steering between two opposite directions is achieved using capacitive MEMS SPDT switches in the router Port impedance and radiation patterns are studied numerically and experimentally Measured results show that the switched beam antenna features a 27% impedance bandwidth (S11 = -10 dB), a gain of 46 dBi, and a front-to-back ratio of 14 dB at 20 GHz when the control voltage is applied to one of the switch pairs of the SPDT switch
49 citations
21 Jun 2009
TL;DR: In this article, a single pole double throw (SPDT)-structured radio frequency microelectromechanical system (RF MEMS) switch for RF applications is proposed, which has a very low insertion loss of 1.0dB and a high isolation of 40dB, up to 10GHz.
Abstract: Here, we propose a practical single pole double throw (SPDT)-structured radio frequency microelectromechanical system (RF MEMS) switch for RF applications. This SPDT switch has a very low insertion loss of 1.0dB and a high isolation of 40dB, up to 10GHz. The fabricated switch is compact in size (5.2×3.0×1.8 mm3) with a Land Grid Array Package. The research and development of an RF MEMS switch has been ongoing in our laboratory for years, and we have achieved practical reliability by using a low vibration actuator against a natural frequency. We describe the correlation between contact reliability and the low vibration actuator, as well as the high frequency performance of our new SPDT switch.
37 citations
01 May 2015-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this article, a single pole double throw (SPDT) RF MEMS switch design based on a torsional series capacitive switch is presented. But the design of the SPDT topology is not discussed.
Abstract: This paper presents a new single pole double throw (SPDT) RF MEMS switch design based on a torsional series capacitive switch. The torsional configuration and use of floating metal reduce the stiction probabilities. Use of a single series capacitive switch compared to the conventional approach of a capacitive and series combination, offers compact size, higher bandwidth and superior reliability. The optimized SPDT topology offers a wider bandwidth of 17 GHz (3---20 GHz) with insertion loss of ?0.3 to ?0.4 dB and isolation ?20 to ?44 dB. The proposed structure actuates at 9 V and the contact force varies in the elastic contact regime from 20 to 68 µN for the bias voltage of 10---15 V.
24 citations
"Fabrication and analysis of radiofr..." refers methods in this paper
...Design part of the switch is described in the earlier paper.(3) In the present paper, S-parameters with experimental results, finite element method (FEM) simulations, and equivalent lumped model are derived and compared....
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