A single-pole double-throw (SPDT) circuit using lateral metal-contact micromachined switches
TL;DR: In this article, a dc 6 GHz single-pole double-throw (SPDT) switching circuit that employs lateral metal-contact micromachined switches is investigated, which consists of a set of quasi-finite ground coplanar waveguide (FGCPW) transmission lines and a high-aspect-ratio cantilever beam.
Abstract: A dc 6 GHz single-pole double-throw (SPDT) switching circuit that employs lateral metal-contact micromachined switches is investigated. The lateral metal-contact switch consists of a set of quasi-finite ground coplanar waveguide (FGCPW) transmission lines and a high-aspect-ratio cantilever beam. A single-pole single-throw (SPST) lateral micromachined switch has an insertion loss of 0.08 dB and a return loss of 32 dB at 5 GHz. The isolation is 32 dB at 5 GHz. The measured insertion loss of the SPDT switching circuit is below 0.75 dB, whereas the return loss is higher than 19 dB at 5 GHz. The isolation at 5 GHz is 33 dB. Pull-in voltage of the switch is 23.3 V and switching time is 35 μs. The size of the SPDT switching circuit is 1.2 mm × 1.5 mm. A main advantage of this circuit structure is simple fabrication process with high yield (>90%) based on the deep reactive ion etching (DRIE) technique of silicon-on-insulator (SOI) wafer and shadow mask technology.
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TL;DR: In this article, a push-pull-type SPDT (single pole double throw) switch is proposed, which combines two switching elements in a single structure, simplifying the overall structure and control signals and eliminating mismatches between the two switches.
Abstract: In this paper, we report a new push-pull-type SPDT (single pole double throw) switch actuated by the combination of electromagnetic and electrostatic forces for low power and low voltage operation. The switch is initially actuated by large electromagnetic force to change its state and is held to maintain its state by applying electrostatic force to reduce static power consumption. The electromagnetic force can be easily generated at low voltage. The maximum actuation voltage is below 4.3 V and the required energy is 15.4 μJ per switching. It achieves signal isolation of −54 dB and insertion loss of −0.16 dB at 2 GHz, respectively. For 20 GHz operation, isolation and insertion loss were measured as −36 dB and −0.52 dB, respectively. The proposed SPDT switch combines two switching elements in a single structure, simplifying the overall structure and control signals and eliminating mismatches between the two switching elements. The dimension of the switch has been optimized using FEM simulation and analytical calculations. We have successfully carried out a lifetime test over more than 166 million cycles with the maximum actuation voltage below 4.3 V. (Some figures in this article are in colour only in the electronic version)
49 citations
Cites background from "A single-pole double-throw (SPDT) c..."
...45 dB −22 dB 47 GHz Nanyang [7] 2 Electrostatic Series 23 V −0....
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TL;DR: In this paper, a mechanically tri-stable switch mechanism based on laterally moving electrostatic curved-electrode actuators is presented, which allows the input signal to be switched between two output ports.
Abstract: This paper reports on a mechanically tri-stable switch mechanism based on laterally moving electrostatic curved-electrode actuators. The switch is configured in a 'true' single-pole-double-throw configuration (SPDT), i.e. a single-switch mechanism allows for the input signal to be switched between two output ports. The switch has three stable states: (1) input to first output; (2) switch off; (3) input to second output. Because of a latching mechanism, these states are mechanically stable, i.e. they are maintained without applying external actuation energy. The fabrication of the switches is done by a single photolithographical step and deep etching of a silicon-on-glass wafer which is subsequently coated with sputtered gold. The switch design features active opening, and the contact force is created passively by the deflected cantilevers. The curved-electrode actuators are utilized close to their end position where they develop their maximum force to guarantee a very large opening force which makes the switch less susceptible for contact stiction. The actuation voltages for different designs and functions of the switches are between 30 and 85 V.
44 citations
TL;DR: In this paper, two-port single-pole-single-throw (SPST) and three-port SPMDT (SPDT) T-junction switches with four mechanically stable states are presented.
Abstract: This paper reports on novel electrostatically actuated dc-to-RF metal-contact microelectromechanical systems (MEMS) switches, featuring a minimum transmission line discontinuity since the whole switch mechanism is completely embedded inside the signal line of a low-loss 3-D micromachined coplanar waveguide. Furthermore, the switches are based on a multistable interlocking mechanism resulting in static zero-power consumption, i.e., both the onstate and the offstate are maintained without applying external actuation energy. Additionally, the switches provide with active opening capability, potentially improving the switch reliability, and enabling the usage of soft low-resistivity contact materials. Both two-port single-pole-single-throw (SPST) switches featuring mechanical bistability and three-port single-pole-double-throw (SPDT) T-junction switches with four mechanically stable states are presented. The switches, together with the transmission lines, are fabricated in a single photolithography process. The loss created by the discontinuity of the switch mechanism alone is 0.08 dB at 20 GHz. Including a 500 m long transmission line with less than 0.4 dB/mm loss up to 20 GHz, the total insertion loss of the two-port devices is 0.15 and 0.3 dB at 2 and 20 GHz, and the isolation is 45 and 25 dB at 2 and 20 GHz. The three-port switches, including their T-junction transmission line, have an insertion loss of 0.31 and 0.68 dB, and an isolation of 43 and 22 dB, at 1 and 10 GHz, respectively. Actuation voltages are 23-39 V for the two-port switches and 39-89 V for the three-port switches. The microwave propagation in the micromachined transmission line and the influence of the different switch designs were analyzed by finite-element method (FEM) simulations of electromagnetic energy and volume current distributions, proving the design advantages of the proposed concept.
43 citations
Cites methods from "A single-pole double-throw (SPDT) c..."
...where either two separate SPST switches are used [29]–[31] or a single mechanism is used with two separate switch contacts [32], all typically positioned at λ/4 distance from the...
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TL;DR: The presented device consists of wireless global positioning system controlled robotics, an electrochemical detector utilizing signal conditioning analog circuitry and a digital feedback range controller, a HVPS, an air pump, and a CE microchip designed for microchip CE.
Abstract: In this paper, the fabrication of a wireless mobile unit containing an electrochemical detection module and a 3-channel high-voltage power supply (HVPS) designed for microchip CE is described. The presented device consists of wireless global positioning system controlled robotics, an electrochemical detector utilizing signal conditioning analog circuitry and a digital feedback range controller, a HVPS, an air pump, and a CE microchip. A graphical user interface (LabVIEW) was also designed to communicate wirelessly with the device, from a distant personal computer communication port. The entire device is integrated and controlled by digital hardware implemented on a field programmable gate array development board. This lab-on-a-robot is able to navigate to a global position location, acquire an air sample, perform the analysis (injection, separation, and detection), and send the data (electropherogram) to a remote station without exposing the analyst to the testing environment.
41 citations
TL;DR: In this article, a meso-scale MEMS inertial switch was fabricated of a?40m thick layer of nickel electrodeposited on top of a 4m thick thermal field oxide (TOX) covering a single crystal silicon wafer.
Abstract: In this work, we report on a novel simple yet robust two-mask metal-on-insulator (MOI) process and illustrate its implementation for the fabrication of a meso scale MEMS inertial switch. The devices were fabricated of a ?40??m thick layer of nickel electrodeposited on top of a 4??m thick thermal field oxide (TOX) covering a single crystal silicon wafer. A 40??m thick layer of KMPR??resist was used as a mold and allowed the formation of high-aspect-ratio (1:5) metal structures. The devices were released by the sacrificial etching of the TOX layer in hydrofluoric acid. The fabricated devices were mounted in a ceramic enclosure and were characterized using both an electromagnet shaker and a drop tester. The functionality of the switch, aimed to trigger an electrical circuit when subjected to an acceleration pulse with amplitude of 300 g and duration of 200??s, was demonstrated experimentally and the performance targets were achieved. The experimental results were consistent with the model predictions obtained through finite element simulations.
32 citations
References
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TL;DR: In this paper, a MEMS switch has been developed for microwave applications with an actuation of 30 V, a response time of 20 /spl mu/s, and mechanical robustness to withstand 10/sup 9/ actuations.
Abstract: A MEMS switch has been developed for microwave applications. The switch has an actuation of 30 V, a response time of 20 /spl mu/s, and mechanical robustness to withstand 10/sup 9/ actuations. An RF performance with >50 dB isolation below 2 GHz and <0.2 dB insertion loss from DC to 40 GHz has been measured.
98 citations
"A single-pole double-throw (SPDT) c..." refers methods in this paper
...The second design is a monolithic SPDT MEMS switching circuit [5,6], which places two MEMS series switches at two output armatures to operate in a 2....
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TL;DR: In this paper, a technique to pattern materials in deep holes and/or on non-planar substrate surfaces using shadow masks is presented. But this technique is not suitable for high-resolution shadow masks.
Abstract: The paper presents a technique to pattern materials in deep holes and/or on non-planar substrate surfaces. A rather old technique, namely, electron-beam evaporation of metals through a shadow mask, is used. The realization of high-resolution shadow masks using micromachining techniques is described. Further, a low ohmic electrical wafer foed-through with a small parasitic capacitance to the substrate and a high placing density is presented.
63 citations
"A single-pole double-throw (SPDT) c..." refers methods in this paper
...Then the SOI wafer was temporarily bonded to a shadow mask [13] using photoresist as intermediate material....
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TL;DR: In this article, two novel lateral metal-contact radio-frequency microelectromechanical system (RF MEMS) switches are reported, implemented with quasi-finite ground coplanar waveguide (FGCPW) configuration and actuated by applying electrostatic force on a high-aspect-ratio cantilever beam.
Abstract: Two novel lateral metal-contact radio-frequency microelectromechanical system (RF MEMS) switches are reported. These switches are implemented with quasi-finite ground coplanar waveguide (FGCPW) configuration and actuated by applying electrostatic force on a high-aspect-ratio cantilever beam. It is demonstrated that the insertion loss of the switch is less than 0.2 dB up to 15 GHz and the isolation is higher than 20 dB up to 25 GHz. An RF model of the switches is used to analyse the effects of the switch design parameters and RF performance. The optimization of the switch mechanical design is discussed where the threshold voltage can be lower than 25 V. The lateral switches are fabricated by deep reactive ion etching (DRIE) process on a silicon-on-insulator (SOI) wafer with shadow mask technology.
58 citations
"A single-pole double-throw (SPDT) c..." refers background in this paper
...Recently, lateral switches have also been studied [9–11]....
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20 May 2001
TL;DR: In this article, single-pole double-throw (SPDT) X and K-band circuit designs incorporating low-loss microelectromechanical shunt capacitive switches are reported.
Abstract: Single-pole double-throw (SPDT) X and K-band circuit designs incorporating low-loss microelectromechanical shunt capacitive switches are reported. The switches incorporate highly inductive connecting beams which aid in further increasing the isolation at the desired operational RF frequency. Measurements show an isolation of better than 40 dB at both 7 and 20 GHz. Insertion loss was measured at -0.95 dB at 7 GHz and -0.69 dB at 20 GHz for the two respective designs.
42 citations
"A single-pole double-throw (SPDT) c..." refers background in this paper
...involves two capacitive shunt MEMS switches placed a quarter wavelength from the center of the T-junction [ 3 ,4]....
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...The insertion loss of 0.81 dB and the isolation of 20.3 dB at X-band [ 3 ], and the insertion loss of 0.43 dB and isolation of 28.7 dB at K-band [3] have been demonstrated....
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...The insertion loss of 0.81 dB and the isolation of 20.3 dB at X-band [3], and the insertion loss of 0.43 dB and isolation of 28.7 dB at K-band [ 3 ] have been demonstrated....
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