81 results about "Mems capacitors" patented technology

A microwave tunable filter having some advantages as follows: a) the integration of MEMS tunable filter and MMIC; b) the very low signal transmission loss and low dispersion; and c) the drastic variation and linear characteristic of frequency by means of MEMS capacitor and an external control signal. The microwave tunable MEMS filter includes a plurality of unit resonant cells, each unit resonant cell being formed by various serial and parallel combination of an inductor, a capacitor, a transmission line, and a variable MEMS capacitor, whereby capacitance variation of the variable MEMS capacitor in the unit resonant cell converts a resonant frequency of the unit resonant cell to thereby convert a center frequency of the filter.

Provided is an oscillator including: a MEMS resonator for mechanically vibrating; an output oscillator circuit for oscillating at a resonance frequency of the MEMS resonator to output an oscillation signal; and a MEMS capacitor for changing a capacitance thereof caused by a change in a distance between an anode electrode and a cathode beam according to an environmental temperature.

An antenna for a wireless device may be kept dynamically tuned to a desired center frequency to compensate for detuning which may be caused by environmental influences. A sensor provides a feedback signal to a controller to select an appropriate capacitance value from a variable capacitor to tune the antenna for the wireless device. The variable capacitor may comprise a plurality of fixed capacitors and MEMS switches arranged in parallel or may comprise a variable MEMS capacitor having a fixed lower plate and a flexible upper plate.

A tire pressure monitoring system is provided that includes a switched capacitor circuit having a clock with two non-overlapping clock phases that control a state of analog switches of the switched capacitor circuit. The system uses tire pressure sensor MEMS capacitors that are measured differentially. A capacitance-to-voltage converter is connected to the MEMS sense capacitor, and a sigma-delta converter having a comparator with a first digital output state and a second digital output state is used. The first output state is a sum of reference voltages and the second output state is a difference of the reference voltages. An average value of the capacitance-to-voltage converter output is driven to a zero value and a digital output is provided of the average output states that is equal to a difference between the MEMS capacitors divided by their sum multiplied by a ratio of the reference voltages.

A tire pressure monitoring system is provided that includes a switched capacitor circuit having a clock with two non-overlapping clock phases that control a state of analog switches of the switched capacitor circuit. The system uses tire pressure sensor MEMS capacitors that are measured differentially. A capacitance-to-voltage converter is connected to the MEMS sense capacitor, and a sigma-delta converter having a comparator with a first digital output state and a second digital output state is used. The first output state is a sum of reference voltages and the second output state is a difference of the reference voltages. An average value of the capacitance-to-voltage converter output is driven to a zero value and a digital output is provided of the average output states that is equal to a difference between the MEMS capacitors divided by their sum multiplied by a ratio of the reference voltages.

The invention relates to a variable capacitor and method of making it. The variable capacitor comprises a fixed charge plate disposed in a substrate, a movable charge plate disposed above the fixed charge plate, and a stiffener affixed to the movable charge plate. The movable charge plate may be patterned to form a movable actuator plate where the fixed charge plate is elevated above a fixed actuator plate.

Various embodiments of tunable capacitors are disclosed. One embodiment is in the form of a tunable capacitor (368) having a pair of stationary capacitor electrodes (392) that are fixed to and disposed the same distance above a substrate (388) in the vertical dimension. A tuning element (416) is suspended above the substrate (388) by an elevation system (460) that accommodates movement of the tuning element (416) in the vertical dimension. Changing the capacitance of the tunable capacitor (368) is accomplished by moving the tuning element (416) in the vertical dimension.

The present invention refers to a flat back plate, e.g. for MEMS capacitors e.g. for MEMS microphones. For that the back plate comprises a tensile element that exerts a horizontal tensile stress on its environment.

The invention relates to a capacitor and a manufacturing technology thereof, in particular to an MEMS (Micro Electro Mechanical System) capacitor based on a three-dimensional silicon micro structure and a manufacturing method thereof, which solve the problems of low load resistance, small volume ratio, poor environmental suitability and poor reliability in the traditional MEMS micro capacitor. The MEMS capacitor based on the three-dimensional silicon micro structure comprises a silicon substrate, wherein a three-dimensional deep groove structure with big specific surface area is formed on the upper surface of the silicon substrate; electrical insulating layers are arranged on the upper surface of the silicon substrate and the cavity surface of the three-dimensional deep groove structure with big specific surface area; lower electrode layers are formed on the upper surfaces of the electric insulating layers; electric medium layers are formed on the upper surfaces of the lower electrode layers; upper electrode layers are formed on the upper surfaces of the electric medium layers; and the lower electrode layer parts are exposed out of the upper electrode layers. The MEMS capacitor based on the three-dimensional silicon micro structure is a full-solid electrostatic MEMS capacitor, which satisfies the development requirements of miniaturization, intellectualization and integration in the fields like fuse power supply, MEMS micro-energy, transportation and the like.

A method is provided of continuously varying the capacitance of a MEMS varactor having a cantilever assembly mounted on a base portion, the cantilever assembly having a first capacitance plate and a dielectric element mounted thereon, and the base portion having a second capacitance plate mounted thereon. The method includes applying a first actuation voltage to deform the cantilever assembly until the dielectric element contacts the second capacitance plate leaving a gap therebetween, and applying a second actuation voltage larger than the first actuation voltage to further deform the cantilever assembly to reduce the gap between the dielectric element and the second capacitance plate.

A system for measuring viscosity includes microfluidic passageways coupled to a micro-cavity, and semiconductive electrodes for applying an electric field across said electrodes. The resultant pressure increase and deflection of the diaphragm changes the capacitance of the MEMS capacitor. Pumps such as a thermal pump or a surface acoustic wave pump control flow of fluid to be measured to and from the micro-cavity. Semiconductor device fabrication techniques are employed to produce the viscosity measurement system.

A voltage controlled oscillator comprising a substrate and a bilayer graphene transistor formed on the substrate. The transistor has two signal terminals and a gate terminal positioned in between the signal terminals. A voltage controlled PZT or MEMS capacitor is also formed on the substrate. The capacitor is electrically connected to the transistor gate terminal. At least one component is connected to the transistor and capacitor to form a resonant circuit.

A fixed parallel plate micro-mechanical systems (MEMS) based sensor is fabricated to allow a dissolved dielectric to flow through a porous top plate, coming to rest on a bottom plate. A post-deposition bake ensures further purity and uniformity of the dielectric layer. In one embodiment, the dielectric is a polymer. In one embodiment, a support layer is deposited onto the top plate for strengthening the sensor. In another embodiment, the bottom plate is dual-layered for a narrowed gap. Integrated circuit arrays of such sensors can be made, having multiple devices separated from each other by a physical barrier, such as a polycrystalline containment rim or trough, for preventing polymer material from one sensor from interfering with that of another.

An antenna for a wireless device may be kept dynamically tuned to a desired center frequency to compensate for detuning which may be caused by environmental influences. A sensor provides a feedback signal to a controller to select an appropriate capacitance value from a variable capacitor to tune the antenna for the wireless device. The variable capacitor may comprise a plurality of fixed capacitors and MEMS switches arranged in parallel or may comprise a variable MEMS capacitor having a fixed lower plate and a flexible upper plate.

The invention relates to a switch linear phase shifter based on a micro electro mechanical system (MEMS) capacitance and inductance phase shifting unit, which comprises MEMS switches, a T-shaped node, a reference phase shifting coplanar waveguide transmission line, an MEMS capacitance and inductance phase shifting transmission line, a transmission line right-angled corner, an MEMS switch electrode, a lead wire, an isolating resistor and a medium substrate. The reference phase shifting coplanar waveguide transmission line and the phase shifting transmission line embedded into an MEMS capacitor and inductor form two transmission paths of the switch linear phase shifter, the MEMS switches are arranged on the T-shaped node and used for strobing the two transmission paths, and the transmission line right-angled corner is used for connecting two sections of transmission lines perpendicular to each other. The switch linear phase shifter based on the MEMS capacitance and inductance phase shifting unit has the advantages that a phase delay unit formed by the MEMS capacitor and inductor effectively reduces integral size of the phase shifter, and a small-sized multi-digit switch linear phase shifter based on the MEMS capacitance and inductance phase shifting unit can be obtained by connecting a plurality of switch linear phase shifters based on the MEMS capacitance and inductance phase shifting unit in cascading mode.

A semiconductor device may include, but is not limited to: a semiconductor substrate; a memory capacitor; and a first compensation capacitor. The semiconductor substrate has at least first and second regions. The memory capacitor is positioned over the first region. The memory capacitor may include, but is not limited to: a first lower electrode; and a first dielectric film covering inner and outer surfaces of the first lower electrode. The first compensation capacitor is positioned over the second region. The first compensation capacitor includes, but is not limited to: a second lower electrode; a second dielectric film covering an inner surface of the second lower electrode; and a first insulating film covering an outer surface of the second lower electrode.

The invention relates to a drive chip having the switch control-based LED light-adjusting and color-temperature-adjusting function. The drive chip comprises a reference voltage generation circuit, a transmission gate array, a transmission gate, a voltage comparison circuit, a decoding circuit and a memory capacitor. The output end of the reference voltage generation circuit is connected with one end of the transmission gate array. The other end of the transmission gate array is connected with one end of the transmission gate. The other end of the transmission gate is connected with the input end of the voltage comparison circuit and the memory capacitor. The output end of the voltage comparison circuit is connected with the input end of the decoding circuit. The output end of the decoding circuit is connected with the control end of the transmission gate array. The switch control-based LED light-adjusting and color-temperature-adjusting function of the drive chip is independent of any extra control unit, such as a MCU, a wireless remote control or other light modulators. Therefore, the peripheral application of the system is simplified, and the cost of the system is reduced. Meanwhile, the popularization of LED lamps in the field of light-adjusting and color-temperature-adjusting systems is effectively facilitated.

The invention discloses an MEMS capacitor switch with a PN junction, and belongs to the technical field of electronics. The MEMS capacitor switch is characterized in that a longitudinal PN junction structure is additionally arranged between an upper drive electrode and a lower drive electrode of the MEMS capacitor switch; when the switch is in the Up state, drive voltage is not applied between the upper drive electrode and the lower drive electrode, and an electric contact point does not make contact with a signal line; when the switch is in the Down state, the upper drive electrode is pulled downwards under the action of the drive voltage, the electric contact point makes contact with the signal line, and meanwhile the longitudinal semiconductor PN junction is in the reversal of biasing state. When the MEMS capacitor switch with the PN junction works in the Down state, charge injection and accumulation cannot be generated, the bonding failure problem of the upper drive electrode and the lower drive electrode is solved, the MEMS capacitor switch is made to work under the sufficient drive voltage, it can be guaranteed that the electric contact point tightly makes contact with the signal line, and eventually reliability and stability of the MEMS capacitor switch can be improved.

A tunable notch filter, comprises a transmission line coupled to an antenna; a plurality of ring resonators inductively coupled to the transmission line, wherein each ring resonator of the plurality of ring resonators is grounded and comprises a variable microelectromechanical systems (MEMS) capacitor; wherein a set of variable MEMS capacitors of the plurality of variable MEMS capacitors are independently tunable to vary a notch location and a notch width of the tunable notch filter; and wherein a set of ring resonators of the plurality of ring resonators further comprises an attenuator configured to reduce power reflected from the antenna.

The invention discloses a zero offset test compensation system of a multi-channel capacitor type MEMS (micro-electromechanical system) acceleration sensor. The zero offset test compensation system comprises a step motor mechanical system, the multi-channel capacitor type MEMS acceleration sensor, a multi-channel data acquisition circuit, a single chip control circuit, an upper computer and a power supply management system, wherein the step motor mechanical system is connected with the multi-channel capacitor type MEMS acceleration sensor; the multi-channel capacitor type MEMS acceleration sensor is connected with a multi-channel data acquisition circuit; the multi-channel data acquisition circuit is connected with the single chip control circuit; the step motor mechanical system comprises an aluminum alloy MEMS capacitor type acceleration sensor carrier body, a step motor and a step motor base; and the step motor is arranged on the step motor base. The zero offset test compensation system can automatically calculate the capacitance deviation of the multi-channel acceleration sensor at the same time, and the zero offset test compensation system has the advantages of being is simple in operation, high in automation level and the like.

The invention relates to a method of manufacturing a microsystem and further to such microsystem. With the method a microsystem can be manufactured by stacking pre-processed foils (10) having a conductive layer (lla, llb) on at least one side. After stacking, the foils (10) are sealed, using pressure and heat. Finally the microsystems are separated from the stack (S). The pre-processing of the foils (preferably done by means of a laser beam) comprises a selection of the following steps: (A) leaving the foil intact, (B) locally removing the conductive layer, (C) removing the conductive layer and partially evaporating the foil (10), and (D) removing both the conductive layer as well as foil (10), thus making holes in the foil (10). In combination with said stacking, it is possible to create cavities, freely suspended cantilevers and membranes. This opens up the possibility of manufacturing various microsystems, like MEMS devices and microfluidic systems.

The invention discloses a pressure sensing chip and a processing method thereof. The chip comprises an upper layer structure and a lower layer structure, wherein the lower layer structure comprises a lower layer substrate piece; MEMS parallel plate capacitors and an MEMS inductor which are connected in series are arranged on the lower layer substrate piece; the upper layer structure comprises upper layer substrate pieces, an MEMS pressure sensing film, an MEMS capacitor dielectric plate and a metal layer; the MEMS pressure sensing film is fixed on the upper layer substrate pieces, and placed above the lower layer substrate piece; the MEMS capacitor dielectric plate and the metal layer are fixed on the lower surface of the MEMS pressure sensing film; the MEMS capacitor dielectric plate is placed in between the two electrode plates of the capacitors; the metal layer is positioned above the MEMS inductor; the MEMS pressure sensing film is pressed to generate longitudinal displacement and drive the MEMS capacitor dielectric plate and the metal layer to move, so that the depth of the MEMS capacitor dielectric plate inserted into the MEMS parallel plate capacitors is changed and a magnetic gap between the metal layer and the MEMS inductor is also changed.

The present invention generally relates to cellular phones having multiple antennas. The invention relates to how two antennas in a diversity or MIMO antenna system interact through mutual coupling. The mutual coupling is due to proximity of the two antennas, their antenna pattern and efficiency. The performance of the system can be optimized by adjusting the mutual coupling between the antennas. The primary and secondary antennas can be "tuned" and "de-tuned" respectively to enhance system performance. In this invention, the primary and secondary antennas are tuned independently using MEMS capacitor configured in the antenna aperture for frequency tuning.

The invention provides an MEMS (Micro Electro Mechanical System) capacitor film vacuum gauge, which can realize the measurement of the vacuum degree in a range of 1-1000Pa, and the measurement resolution is 0.5 Pa. A pressure sensing film is a circular film with an island-shaped structure film. The circular film is very uniform in radial stress and strain, and under the same pressure, the deflection of the circular film is larger than that of a square film, so that the sensitivity of the pressure sensing film is higher. The island-shaped structure film can increase the rigidity of the film, sothat the deflection of the pressure sensing film is reduced, the basic capacitance is increased, the resolution ratio is improved, and meanwhile, the linearity of the pressure-capacitance relationship is better. Meanwhile, the circular film with the island-shaped structure film is of a double-side electrode differential type sensitive capacitor structure. When the pressure sensing film deforms due to pressure, the sensitive capacitor outputs two capacitances which are equal in variation and opposite in direction, and a double-differential structure is formed through a subsequent differentialmeasurement circuit, so that the common-mode rejection ratio is improved, the influence of parasitic capacitance, temperature and other factors on a measurement result is eliminated, and the measurement resolution is improved.