278results about "Capacitor with electrode area variation" patented technology

A variable capacitor is formed by a multilayer circuit board having a plurality of dielectric layers; a first conductive plate, provided within the multilayer circuit board, for serving as one electrode of the variable capacitor; a second conductive plate, provided within the multilayer circuit board, for serving as the other electrode of the variable capacitor; a plurality of third conductive plates provided between the first conductive plate and the second conductive plate; and a plurality of switching means provided for grounding the third conductive plates selectively.

Nano-electromechanical device having an electrically conductive nano-cantilever wherein the nano-cantilever has a free end that is movable relative to an electrically conductive substrate such as an electrode of a circuit. The circuit includes a power source connected to the electrode and to the nano-cantilever for providing a pull-in or pull-out voltage therebetween to effect bending movement of the nano-cantilever relative to the electrode. Feedback control is provided for varying the voltage between the electrode and the nano-cantilever in response to the position of the cantilever relative to the electrode. The device provides two stable positions of the nano-cantilever and a hysteresis loop in the current-voltage space between the pull-in voltage and the pull-out voltage. A first stable position of the nano-cantilever is provided at sub-nanometer gap between the free end of the nano-cantilever and the electrode with a pull-in voltage applied and with a stable tunneling electrical current present in the circuit. A second stable position of the nano-cantilever is provided with a pull-out voltage between the cantilever and the electrode with little or no tunneling electrical current present in the circuit. The nano-electromechanical device can be used in a scanning probe microscope, ultrasonic wave detection sensor, NEMS switch, random access memory element, gap sensor, logic device, and a bio-sensor when the nano-cantilever is functionalized with biomolecules that interact with species present in the ambient environment be them in air or aqueous solutions. In the latest case, the NEMS needs to be integrated with a microfluidic system.

A MEMS tunable capacitor with angular vertical comb-drive (AVC) actuators is described where high capacitances and a wide continuous tuning range is achieved in a compact space. The comb fingers rotate through a small vertical angle which allows a wider tuning range than in conventional lateral comb drive devices. Fabrication of the device is straightforward, and involves a single deep reactive ion etching step followed by release and out-of-plane assembly of the angular combs.

A three-dimensional micro electro-mechanical (MEMS) variable capacitor is described wherein movable comb electrodes of opposing polarity are fabricated simultaneously on the same substrate are independently actuated. These electrodes are formed in an interdigitated fashion to maximize the capacitance of the device. The electrodes are jointly or individually actuated. A separate actuation electrode and a ground plane electrode actuate the movable electrodes. The voltage potential between the two electrodes provides a primary mode of operation of the device. The variation of the sidewall overlap area between the interdigitated fingers provides the expected capacitance tuning of the device. The interdigitated electrodes can also be attached on both ends to form fixed-fixed beams. The stiffness of the electrodes is reduced by utilizing thin support structures at the ends of the electrodes. The three dimensional aspect of the device avails large surface area. Large capacitance variation and tuning ranges are obtained by independent actuation of the electrode fingers. A plurality of modes of operation of the device provides wide flexibility and greater performance advantage for the device. Upon fabrication of the device, a separate substrate with etched dielectric is used to encapsulated the device. The MEMS device is then completely encapsulated, requiring no additional packaging of the device. Further, since alignment and bonding can be done on a wafer scale, an improved device yield is obtained at a lower cost.

An embodiment of the present invention provides a device, comprising a multilayered tunable dielectric capacitor, wherein said multilayers of tunable dielectric are adapted to be DC biased to reduce the dielectric constant; and wherein the DC bias is arranged so that the number of layers of tunable dielectric biased positively is equal to the number of layers of tunable dielectric biased negatively.

Disclosed are a humidity sensor and a fabricating method thereof. The humidity sensor includes a substrate, an anodic aluminum oxide layer formed on the substrate and having a plurality of holes, and electrodes formed on the anodic aluminum oxide layer, in order to improve sensitivity and accuracy of the humidity sensor. Further, the fabricating method of a humidity sensor includes preparing an aluminum substrate, forming an anodic aluminum oxide layer by oxidizing the aluminum substrate, and forming electrodes on the anodic aluminum oxide layer.

One embodiment of the present invention relates to a variable capacitor that operates without moving mechanical parts. In this capacitor electrically conductive electrodes are separated by an enclosed chamber filled with an electrically conductive material. The electrically conductive material can freely vary its position within the chamber. The capacitance of the device will vary as position of the conductive material changes due to external mechanical motion (ex: rotation vibration, etc.) of the device. Other embodiments of this device are also disclosed.

An exemplary light emitting diode (LED) assembly includes a cover, a substrate, a LED unit, a first electrode terminal, and a second electrode terminal. The substrate includes a first surface and a second surface on an opposite side of the substrate thereto. The substrate and the cover cooperatively define a cavity. The LED unit is received in the cavity. The first and the second electrode terminals extend from the second surface. The first electrode terminal is electrically connected to one of a positive lead and a negative lead of the LED unit and the second electrode terminal is electrically connected to the other. The second electrode terminal includes a first electrode portion and a second electrode portion symmetrically arranged at opposite sides of the first electrode terminal. The first and the second electrode portions are at least partially symmetrical with respect to the first electrode terminal.

A variable capacitance element includes a movable element provided above a substrate using supporting portions and support beams so as to be displaced from the substrate. An insulating film and a movable electrode are provided on a conductor facing surface of the movable element. A driving electrode is arranged to displace the movable element, between a signal cutoff position and a signal passage position, whereby a high frequency signal transmitted through a transmission line is cut off or allowed to pass. The insulating film uses compressive stress to warp the movable element and the movable electrode in a direction of warping in a convex form toward the transmission line, and maintains this warping direction.

A variable passive component is provided for fabrication on a microelectromechanical system (MEMS) device. A conductive portion is provided on a low-profile sliding dielectric sheet that cooperates with a conductive portion disposed on a substrate to provide a variable passive component. The passive component can be a variable inductor provided by moving a shorted spiral inductor formed on the dielectric sheet over a spiral inductor on the substrate with varying degrees of overlap causing varying inductance values. The passive component can be a variable capacitor that consists of a large conductive pad on a dielectric plate which slides over two adjacent pads on the substrate with varying overlap causing varying capacitance values.

A method is for fabricating an integrated circuit formed from a substrate and including several metallic interconnection levels in which, in a same plane parallel to the main plane of the substrate, is a plurality of thick horizontal metallic interconnection lines, as well as one or several MIM capacitors fitted with metallic electrodes that are orthogonal to the main plane of the substrate.

A variable capacitor is provided which is appropriate for suppressing fluctuation in driving voltage characteristic and for achieving a larger variation ratio of static capacitance. The variable capacitor includes a fixed electrode and a movable electrodetrode. The fixed electrode includes a first opposing face, while the movable electrode includes a second opposing face that faces the first opposing face. The movable electrode further includes a curved portion that protrudes toward the fixed electrode. The variable capacitor also includes a dielectric pattern provided on the first opposing face.

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.

There is provided a variable device circuit according to the present invention, including: a substrate; at least one movable switch device formed on a first principal surface of the substrate; at least one fixed capacitor device formed on the first principal surface of the substrate; at least one variable capacitor device formed on the first principal surface of the substrate; at least one variable inductor device formed on the first principal surface of the substrate; and wiring lines for electrically connecting the devices to one another, the wiring lines being formed on the first principal surface of the substrate; wherein electrical connections among the devices can be selected by operation of the movable switch device, whereby achieving stable, low-loss circuit characteristics with lower manufacturing cost.

In a solenoid valve, a boss portion is formed integrally with an attracting portion of a stator core at an outer peripheral side of the attracting portion. The boss portion has a tapered outer peripheral surface and a tapered inner peripheral surface. A plunger has a communication passage, which extends through the plunger generally along a central axis of the plunger.