Design Of MEMS Switch Research Articles

Compact low-loss high-performance single-pole six-throw RF MEMS switch design and modeling for DC to 6 GHz

Low-loss high-performance systems with smaller footprints are highly regarded in the area of radio-frequency (RF) applications. In this paper, a multi-port single-pole six-throw (SP6T) based on RF MEMS ohmic switches design is proposed. The complete switch is designed with very small footprints of 1.2 mm$$^2$$2. Six ohmic/series microelectromechanical (MEMS) switches are designed to get high-isolation in microwave frequency range. The spring constant and actuation voltage required for the operation of the switches is computed using stress analysis module of finite element modeler. The robustness issue of RF MEMS switches can be increased by the proposed geometry. Based on the calculations and simulations, it can be seen that the switches can easily withstand the stress of $$\approx$$?120 MPa. The simulated RF performance of SP6T switch exhibits isolation of 70---45 dB and insertion loss of 0.01 dB for DC to 6 GHz between input port and individual output port. The proposed SP6T switch require low operational voltage level of 12.5 V.

A fabrication process based on structural layer formation using Au–Au thermocompression bonding for RF MEMS capacitive switches and their performance

This paper presents a radio frequency micro-electro-mechanical-systems (RF MEMS) fabrication process based on a stacked structural layer and Au–Au thermocompression bonding, and reports on the performance of a sample RF MEMS switch design implemented with this process. The structural layer consists of 0.1 µm SiO2/0.2 µm SixNy/1 µm Cr–Au layers with a tensile stress less than 50 MPa deposited on a silicon handle wafer. The stacked layer is bonded to a base wafer where the transmission lines and the isolation dielectric of the capacitive switch are patterned. The process flow does not include a sacrificial layer; a recess etched in the base wafer provides the air gap instead. The switches are released by thinning and complete etching of the silicon handle wafer by deep reactive ion etching (DRIE) and tetramethylammonium hydroxide (TMAH) solution, respectively. Millimeter-wave measurements of the fabricated RF MEMS switches demonstrate satisfactory up-state performance with the worst-case return and insertion losses of 13.7 and 0.38 dB, respectively; but the limited isolation at the down-state indicates a systematic problem with these first-generation devices. Optical profile inspections and retrospective electromechanical analyses not only confirm those measurement results; but also identify the problem as the curling of the MEMS bridges along their width, which can be alleviated in the later fabrication runs through proper mechanical design.

Design of compact and wide bandwidth SPDT with anti-stiction torsional RF MEMS series capacitive switch

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.

Design and Modelling of a Silicon Optical MEMS Switch Controlled by Magnetic Field Generated by a Plain Coil

Optical switches can be made as a silicon cantilever with a magnetic layer. Such a structure is placed in a magnetic field of a planar coil. There is a torque deflecting the silicon beam with NiFe layer depending on a flux density of the magnetic field. The study shows an analysis of ferromagnetic layer parameters, beam's dimensions on optical switch characteristics. Different constructions of the beams were simulated for a range of values of magnetic field strength from 100 to 1000 A/m. An influence of the actuators parameters on characteristics was analysed. The loss of stiffness of the beam caused by specific constructions effected in displacements reaching 85 nm. Comsol Multiphysics 4.3b was used for the simulations.

Design of MEMS switch for RF applications

Components like passive electronically scanned (sub) arrays, T/R modules, reconfigurable antennas etc., in RF applications are in need of MEMS switches for its re-configurability and polarization. This paper presents the analysis, design and simulation of a MEMS switch. The switch proposed in this paper is intended to work in the frequency range of 4–8 GHz. The proposed switch fulfills the switching characteristics concerning the five requirements loss, linearity, high switching speed, small size/power consumption, low pull down voltage following a relatively simple design, which ensures reliability, robustness and high fabrication yield. The switch implemented in this paper is based on the integration mode of operation and widely used in RF applications.

Multiactuation complementary metal-oxide semiconductor radio frequency MEMS switch

A complementary metal-oxide semiconductor (CMOS)-compatible, capacitive, shunt-type radio frequency MEMS switch design is demonstrated. The switch is actuated by an electrothermal actuator and an electrostatic actuator at the same time, and the switching status is latched by electrostatic force only. Since thermal actuators require a lower voltage than electrostatic actuators, and since an electrostatic force can maintain switching status with virtually no power, the benefits of the mechanism are a very low actuation voltage and low power consumption. The switch is fabricated by a standard 0.35-µm 2P4M CMOS process. The movable membrane can be released by either wet or dry postprocessing etching technologies. The design's CMOS-process compatibility is important because radio frequency (RF) characteristics are determined not just by the device itself. The design can minimize parasitic capacitance when a packaged RF switch and a packaged IC are wired together. The switch contains a set of coplanar waveguide transmission lines and a suspended membrane. The CPW lines and the membrane are contained in the metal layers of the CMOS process. The electrothermal actuators are contained in the polysilicon layer. Only standard CMOS process layers are needed for both the electrothermal and electrostatic actuations in the RF switch. The measurement results show that the electrothermal or electrostatic actuation requires less than 7 V.

See-saw Type RF MEMS Switch with Narrow Gap Vertical Comb

This paper presents the see-saw type RF MEMS switch based on a single crystalline silicon structure with narrow gap vertical comb. Low actuation voltage and high isolation are key features to be solved in electrostatic RF MEMS switch design. Since these parameters in conventional parallel plate RF MEMS switch designs are in trade-off relationship, both requirements cannot be met simultaneously. In the vertical comb design, however, the actuation voltage is independent of the vertical separation distance between the contact electrodes. Therefore, the large separation gap between contact electrodes is implemented to achieve high isolation. We have designed and fabricated RF MEMS switch which has 46dB isolation at 5GHz, 0.9dB insertion loss at 5GHz and 40V actuation voltage.

Modeling microwave behaviors of series cantilever MEMS switch

Simple and effective model is demanded which enables the design and structural optimization of the microwave MEMS switch efficiently. For this purpose the microwave behaviors of series metal cantilever MEMS switch have been modeled by “simple” circuit in this paper. The microwave characteristics have been calculated and compared with the experiment data based on the developed model. The results show that the microwave characteristics of series metal cantilever MEMS switch can be described very well with this model. Based on this model, the influences of the structural parameters of the switch on the microwave characteristics have been discussed extensively.

An Analytical Model for High Performance Capacitive RF MEMS Switch Design

An Analytical Model for High Performance Capacitive RF MEMS Switch Design