A novel interdigitated, inductively tuned, capacitive shunt RF — MEMS switch for X and K bands applications
13 Apr 2014-pp 139-142
TL;DR: A new type of capacitive shunt RF-MEMS switch used to inductively tune the isolation peaks in X and K bands which is not possible with conventional approach and can be useful for the future multiband communication applications.
Abstract: This paper presents a new type of capacitive shunt RF-MEMS switch. In the proposed design, interdigitation of signal lines with actuation electrodes is used to make a compact device. A bridge structure anchored in between ground planes and attached to two cantilevers on either side has been used to implement the switch structure. This novel structure is used to inductively tune the isolation peaks in X and K bands which is not possible with conventional approach. The designed switch shows an insertion loss of 0.01 dB to 0.11 dB over the frequency range from 1 to 25 GHz. Isolation of 34.71, 34.33, and 40.7 dB has been observed at 10.4 GHz, 11 GHz and 21.4 GHz when bridge is electro-statically actuated with either left, right or both cantilevers in the down state respectively. The bridge structure shows a pull-in voltage of 12.25 V and switching time of 34.40 μs whereas left and right cantilevers have 7.5 V and 57 μs. The designed device can be useful for the future multiband communication applications.
Citations
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TL;DR: The research status of MEMS switches in different bands and several reliability issues, such as dielectric charging, contact failure, and temperature instability are introduced.
Abstract: Due to their high isolation, low insertion loss, high linearity, and low power consumption, microelectromechanical systems (MEMS) switches have drawn much attention from researchers in recent years. In this paper, we introduce the research status of MEMS switches in different bands and several reliability issues, such as dielectric charging, contact failure, and temperature instability. In this paper, some of the following methods to improve the performance of MEMS switches in high frequency are summarized: (1) utilizing combinations of several switches in series; (2) covering a float metal layer on the dielectric layer; (3) using dielectric layer materials with high dielectric constants and conductor materials with low resistance; (4) developing MEMS switches using T-match and π-match; (5) designing MEMS switches based on bipolar complementary metal–oxide–semiconductor (BiCMOS) technology and reconfigurable MEMS’ surfaces; (6) employing thermal compensation structures, circularly symmetric structures, thermal buckle-beam actuators, molybdenum membrane, and thin-film packaging; (7) selecting Ultra-NanoCrystalline diamond or aluminum nitride dielectric materials and applying a bipolar driving voltage, stoppers, and a double-dielectric-layer structure; and (8) adopting gold alloying with carbon nanotubes (CNTs), hermetic and reliable packaging, and mN-level contact.
32 citations
Cites background or methods from "A novel interdigitated, inductively..."
...[42] designed a new type of capacitive shunt MEMS switch with float metal layers for the X and K bands and showed a low insertion loss of 0....
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...designed a new type of capacitive shunt MEMS switch for the X and K bands [42]....
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...A low-actuation voltage was achieved in [39,40,42] using two actuation electrodes and cantilevers with a low spring constant....
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TL;DR: In this paper, float metal concept is utilized to reduce the RF overlap area between the movable structure and central conductor of CPW for improving the insertion loss of the device, which has been achieved without affecting the downstate response.
22 citations
01 Oct 2015-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this paper, the authors proposed a new type of capacitive shunt RF-MEMS switch, which consists of a beam in the form of two symmetric cantilevers anchored at the central conductor of CPW, where they generate a fixed capacitance.
Abstract: This paper presents a new type of capacitive shunt RF-MEMS switch. In the proposed design, switch consists of a beam in the form of two symmetric cantilevers anchored at the central conductor of CPW, where they generate a fixed capacitance, whereas the free ends of the cantilevers are hanging over the ground plane of the CPW. The net up-state capacitance thus can be approximately determined from the area of overlap between the ground plane and free ends of cantilevers rather than the central overlap area as in the case of conventional movable bridge based approach. Further, the switch is used to inductively tune the isolation peaks in C and X bands i.e. 44.53 dB at 4.5 GHz and 51.08 dB at 9.8 GHz, when either or both cantilevers are electro-statically actuated to the down-state position. The device with movable bridge has isolation peak only at a single frequency in X band. Device shows an insertion loss less than 0.15 dB, a return loss below 21.38 dB up to 25 GHz as compared to 1.00 dB insertion, 7.67 dB return loss for the equivalent conventional switch with movable bridge. In addition, improvement of around 3.5 times in the bandwidth and 50 % reduction in the pull-in voltage has also been achieved. The designed switch can be useful at device and sub-system level for the future multi-band communication applications.
12 citations
TL;DR: A novel capacitive shunt RF-MEMS switch using broadside bridge structure joined with two cantilevers on either side has been used and the model has been implemented in commercially available software.
Abstract: This paper presents a novel capacitive shunt RF-MEMS switch. In the proposed design, broadside bridge structure joined with two cantilevers on either side has been used to implement the switch. The transmission line and actuation electrodes under the bridge are designed in the interdigitated form to reduce the area. Switch shows an insertion loss better than 0.11 dB, a return loss below 23.67 dB up to 25 GHz. In down-state, three resonant peaks of 34.71, 34.33 and 40.7 dB at 10.4, 11.0 and 21.4 GHz have been achieved as compared to a single peak in the case of the conventional switch. The proposed device has a bandwidth of 2.2 GHz in X-band and 5.2 GHz in K-band. Bridge structure shows a pull-in voltage of 12.25 V, actuation time of 34.40 µs while cantilevers have 7.5 V and 57 µs. Further, the electrical equivalent model has been presented to represent the switch. The model has been implemented in commercially available software. A good agreement with the 3-D electromagnetic simulated results validates the presented model.
8 citations
16 Mar 2020-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this paper, the design and simulation of RF MEMS shunt capacitive switch has been done using COMSOL(FEM) and HFSS tools, and the switch has the design with non-uniform meanders and dielectric material Silicon Nitrate (Si3N4).
Abstract: This paper presents, the design and simulation of RF MEMS shunt capacitive switch. The electromechanical and electromagnetic analysis of the switch has been done using COMSOL(FEM) and HFSS tools. The proposed switch has the design with non-uniform meanders and dielectric material Silicon Nitrate (Si3N4). Different beam materials such as Gold, Aluminum, and Platinum are used to design the switch and analyze it. In the electro mechanical analysis of the switch, the pull-in voltage obtained for the beam material Platinum is 10.56 V for a gap (between the beam and signal-line dielectric) of 2.5 µm which is effective in comparison to the other materials like Gold and Aluminum. As far as the RF performance analysis is concerned, the isolation, insertion loss and return loss have been calculated. The isolation, return loss and insertion loss are − 25 dB, − 14.3 dB and − 0.33 dB respectively. On performing the stress analysis of the switch, a stress value of 0.05 N/m2 has been obtained for the applied pull-in voltage. The proposed switch is used for C band applications.
5 citations
References
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Book•
01 Jan 2003
TL;DR: In this paper, the basics of RF MEMS and how to design practical devices and circuits are discussed, as well as expert tips for designers and a range of real-world applications.
Abstract: From the Publisher:
Practical and theoretical coverage of RF MEMS for circuits and devices
New RF and microwave frequency MEMS (microeletromechanical systems) have potentially enormous and widespread applications in the telecommunications industry. Components based on this technologysuch as switches, varactors, and phase shiftersexhibit virtually no power consumption or loss, making them ideally suited for use in modern telecommunications and wireless devices.
This book sets out the basics of RF MEMS and describes how to design practical devices and circuits. As well as covering fundamentals, Gabriel Rebeiz offers expert tips for designers and presents a range of real-world applications. Throughout, the author utilizes actual engineering examples to illustrate basic principles in theory and practice. Detailed discussion of cutting-edge fabrication and packaging techniques is provided.
Suitable as a tutorial for electrical and computer engineering students, or as an up-to-date reference for practicing circuit designers, RF MEMS provides the most comprehensive available survey of this new and important technology.
Author Biography: Gabriel M. Rebeiz received his PhD from the California Institute of Technology, and is Professor of Electrical and Computer Engineering at the University of Michigan, Ann Arbor. In 1991 he was the recipient of the National Science Foundation Presidential Young Investigator Award, and in 2000 was the corecipient of the IEEE Microwave Prize. A Fellow of the IEEE and a consultant to Rockwell, Samsung, Intel, Standard MEMS, and Agilent, he has published extensively in the field of microwave technology and in the area of RF MEMS.
1,895 citations
TL;DR: In this article, the electrostatic microswitch is used in a number of existing circuits and systems, including radio front-ends, capacitor banks, and time-delay networks, for quasi-optical beam steering and electrically reconfigurable antennas.
Abstract: This paper deals with a relatively new area of radio-frequency (RF) technology based on microelectro-mechanical systems (MEMS). RF MEMS provides a class of new devices and components which display superior high-frequency performance relative to conventional (usually semiconductor) devices, and which enable new system capabilities. In addition, MEMS devices are designed and fabricated by techniques similar to those of very large-scale integration, and can be manufactured by traditional batch-processing methods. In this paper, the only device addressed is the electrostatic microswitch - perhaps the paradigm RF-MEMS device. Through its superior performance characteristics, the microswitch is being developed in a number of existing circuits and systems, including radio front-ends, capacitor banks, and time-delay networks. The superior performance combined with ultra-low-power dissipation and large-scale integration should enable new system functionality as well. Two possibilities addressed here are quasi-optical beam steering and electrically reconfigurable antennas.
685 citations
TL;DR: In this article, the LC series resonance of the shunt switch was used to tune two and four-bridge "cross" switches from 10 to 40 GHz with an insertion loss of less than 0.3-0.6 dB, a return loss below -20 dB from 22 to 38 GHz in the up state, and a downstate isolation of 45-50 dB with only 1.5 pF of downstate capacitance.
Abstract: For pt.1 see ibid., vol.48, no.6, p.1045-1052 (2000). In this paper, the second of two parts, the equivalent RLC model of the shunt switch is used in the design of tuned two- and four-bridge "cross" switches from 10 to 40 GHz. The cross switch attained an insertion loss of less than 0.3-0.6 dB, a return loss below -20 dB from 22 to 38 GHz in the up state, and a down-state isolation of 45-50 dB with only 1.5 pF of down-state capacitance (C/sub d/). Also, an X-band microelectromechanical system (MEMS) switch with an insertion loss of less than 0.2 dB and an isolation of 35 dB is presented. This is done by inductively tuning the LC series resonance of the shunt switch. The MEMS bridge height is 1.5-2.5 /spl mu/m, resulting in a pull-down voltage of 15-25 V. Application areas are in low-loss high-isolation communication and radar.
320 citations
TL;DR: In this article, the progress in RF-MEMS from a device and integration perspective is reviewed, and the worldwide state-of-the-art of RFMEMS devices including switches, variable capacitors, resonators and filters are described.
Abstract: Wireless communication has led to an explosive growth of emerging consumer and military applications of radio frequency (RF), microwave and millimeter wave circuits and systems. Future personal (hand-held) and ground communications systems as well as communications satellites necessitate the use of highly integrated RF front-ends, featuring small size, low weight, high performance and low cost. Continuing chip scaling has contributed to the extent that off-chip, bulky passive RF components, such as high-Q inductors, ceramic and SAW filters, varactor diodes and discrete PIN diode switches, have become limiting. Micro-machining or MEMS technology is now rapidly emerging as an enabling technology to yield a new generation of high-performance RF-MEMS passives to replace these off-chip passives in wireless communication (sub)systems. This paper reviews the progress in RF-MEMS from a device and integration perspective. The worldwide state-of-the-art of RF-MEMS devices including switches, variable capacitors, resonators and filters are described. Next, it is stipulated how integration of RF-MEMS passives with other passives (as inductors, LC filters, SAW devices, couplers and power dividers) and, active circuitry (ASICs, RFICs) can lead to the so-called RF-MEMS system-in-a-package (RF-MEMS-SiP) modules. The evolution of the RF-MEMS-SiP technology is illustrated using IMEC's microwave multi-layer thin-film MCM-D technology which today already serves as a technology platform for RF-SiP.
250 citations
TL;DR: In this paper, a symmetric toggle switch (STS) is proposed for 8-14 GHz applications with low actuation voltage and high isolation, for high power and reliability applications in telecommunication.
Abstract: In this paper, we present a new type of rf MEMS switch with low actuation voltage and high isolation, for high rf power and reliability applications in telecommunication. ‘Symmetric toggle switch’ (STS) is based on push–pull mechanism and utilizes torsion springs and levers, placed symmetrically and transverse to CPW line. The switches designed for 8–14 GHz applications have analytically calculated and FEM simulated actuation voltages in the range of 8–10 V. The simulated insertion loss and isolation for the devices are 0.25 and 35 dB, respectively, at 10 GHz. The fabrication process and preliminary experimental results are also presented.
66 citations
"A novel interdigitated, inductively..." refers background in this paper
...literature for the switches which have high isolation but can’t be tuned for different bands [5]-[8]....
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