Frequency translation and applications of same are described herein, including wireless local area network (WLAN) applications such as IEEE Standard 802.11 WLANs. Such applications include, but are not limited to, frequency down-conversion, frequency up-conversion, enhanced signal reception, unified down-conversion and filtering, and combinations and applications of same.

Wireless local area network (WLAN) technology and applications including techniques of universal frequency translation

Capacitance measurement apparatus that enhances the sensitivity and accuracy of capacitive transducers, proximity sensors, and touchless switches. Each of two capacitors (C 1 , C 2 ) under measurement has one end connected to ground and is kept at substantially the same voltage potential by operational amplifier (A 1 ) or amplifiers (A 0 , A 1 ) using negative feedback. The apparatus is driven by a periodic e.g. sinusoidal signal source (G 1 ) or sources (G 1 , G 2 ) and includes a difference amplifier (A 2 ) operative to produce an electrical signal having a linear relationship with a specified arithmetic function of the capacitances of the two capacitors (C 1 , C 2 ). A touchless switch is implemented using the capacitance measurement apparatus. The touchless switch includes two sensor electrodes (E 1 , E 2 ) that correspond to the two capacitors (C 1 , C 2 ) under measurement and in one embodiment has a front surface in the form of a container.

Linear capacitance measurement and touchless switch

A symmetrical micromechanical gyroscope includes an inertial mass symmetrically supported about both drive and sense axes, for detecting rotational movement about an input axis Two pairs of flexures attached to diametrically opposed sides of the inertial mass support the mass within a gyroscope support frame Each of the flexures are oriented at generally a 45° angle from both the drive and the sense axes In response to an applied drive signal, the inertial mass is induced to vibrate about a drive axis which is co-planar with and orthogonal to the sense axis Both pair of flexures participate equally during rotation of the mass

Symmetrical micromechanical gyroscope

A bridge electrode structure and method of fabrication thereof is provided that is adapted to provide electrically isolated metal bridges over the active portions of a monolithic micromechanical transducer. The bridge electrode of the invention is also adapted to operate in facing relationship with one or more buried electrodes, providing top-to-bottom symmetry for balanced application of forces, or motion detection when used in conjunction with transducer elements. The transducer, typically a gyroscope or an accelerometer, includes a semiconductor substrate and active elements etched out of the substrate, the active elements including flexure-supported transducer plates. The bridge electrodes are anchored at opposing points on the substrate's surface to metal layers used to facilitate their electro-forming. The central portions of the bridge are electroplated over an insulating spacer, such as a photoresist layer.

Bridge electrodes for microelectromechanical devices

An implantable medical device communication system communicates information between an implantable medical device and at least one slave device by way of a two-wire bus. Slave devices may include remote sensors and other implantable medical devices. The implantable medical device includes a communication unit to combine data and power for transmission over the two-wire bus. The transmitted signal is selectively changeable between a first and second voltage. The slave device includes a recovery unit to recover data and power from the received signal. An extendable command set includes long commands to set up the system and shorter commands to conserve power. Selectively addressable multicast commands, and shortened quick trigger commands conserve power by lowering system current and increasing data throughput.

Implantable medical device communication system

In a switched-capacitor type interface circuit connected to a capacitive sensor having two capacitors (C1, C2) whose value is variable, the interface circuit includes an operational amplifier (A1) with an output terminal and an inverting input terminal between which a feedback/sampling capacitor (C3) is connected, and a holding capacitor (C4) connected between the operational amplifier (A1) and a reference voltage source. The capacitors (C1, C2, C3) have one ends connected to the inverting input terminal of the operational amplifier (A1). The other ends of the capacitors (C1, C2) are connected to a power source and the capacitor (C3) is concurrently short-circuited depending upon predetermined timing, and the other ends of the and capacitors (C1, C2) and the output terminal of the operational amplifier (A1) are respectively connected to a non-inverting input terminal of the operational amplifier (A1) after the elapse of a predetermined time from the predetermined timing.

capacitive sensor interface circuit

PROBLEM TO BE SOLVED: To provide an angular velocity sensor with higher sensitivity and precision by obtaining a stable driving vibration as well as reducing influence of a mechanical coupling. SOLUTION: The angular velocity sensor is capable of detecting at least one angular velocity of one axial direction among three directional axses perpendicular to each other. The sensor is provided with a beam structure body suspended via an elastic beam on a substrate. The beam structure body is composed of a pair of driving frames and detection frames. As for the driving frames, each frame is supported at least by a pair of elastic beams, connected to both the sides of the connection part via a pair of driving beams, and vibrated toward the 1st or 2nd axial direction parallel to the substrate surface. The detection frames are connected by the connection part, arranged point to point symmetry to the 1st and/or 2nd axial direction regarding the center of the connection part, and provided with a pair of detection mass body suspended by a detection beam capable of vibrating toward detecting direction, and vibrates around the 3rd axis perpendicular to the substrate surface by vibration the driving frame. The displacement of the detection mass body to the 3rd axis direction generated by the angular velocity is detected by the detection electrode provided on the substrate. COPYRIGHT: (C)2005,JPO&NCIPI

Angular velocity sensor

A semiconductor acceleration sensor, including a semiconductor substrate, in which a mounting portion is formed in the substrate, and first and second cantilevered beams are formed in the substrate in opposite sides of the mounting portion so that these three members are aligned along a straight line, and in which a weight is formed at an end of the first cantilevered beam, and first and second strain sensing devices are formed in approximately the same layout in surface portions of the first and second cantilevered beams, respectively

Semiconductor acceleration sensor

In an interface circuit connected to a capacitance type sensor having two sets of capacitors C1 and C2 whose capacitances are varied, this interface circuit is equipped with an OP amplifier A1 where a feedback/sampling capacitor C3 is connected between its output terminal and its inverting input terminal; and a holding capacitor C4 connected between a non-inverting terminal of the OP-amplifier A1 and a reference voltage source; one ends of the respective capacitors C1, C2, C3 are connected to the inverting input terminal of the OP amplifier A1; at timing φ1 of a switching cycle, the other ends of the respective capacitors C1, C2 are connected to a power source and the capacitor C3 is shortcircuited; at timing φ2 thereof, the other ends of the capacitors C1, C2 and an output terminal of the OP amplifier A1 are connected to the non-inverting input terminal of the OP amplifier A1; and the switched capacitor type interface interface circuit further includes: a multiplexer for sequentially connecting a plurality of the capacitance type sensors to the capacitance type sensor interface circuit in a second switching cycle having a time period longer than time periods of the switching cycles φ1 and φ2; and a plurality of sample/hold circuits whose quantity is equal to those of the plural capacitance type sensors, which are sequentially connected to the capacitive type sensor interface circuit in response to the connections of the plural capacitance type sensors in the second switching cycle.

Capacitance type sensor interface circuit

An interface circuit for a capacitive sensor capable of outputting a detection signal with high stability and reliability while suppressing to a minimum the influence of offset and temperature dependency onto the output signal. In a differential capacitance type sensor having a common electrode connected to the ground potential, an electric discharge redistributing method and impedance conversion technique are adopted for obtaining an output voltage which is in proportion to the inter-electrode relative displacement. A switching mechanism is provided for mitigating an offset voltage component contained in the output due to an input offset voltage of the operational amplifier. Further, the sensitivity of the capacitive sensor is increased with the temperature-dependent drift of the sensor output being suppressed by providing additionally a power source change-over switches for allowing the voltages sampled in response to predetermined clocks to be differentially amplified.

Masahiro Tsugai

Papers

capacitive sensor interface circuit

Angular velocity sensor

Semiconductor acceleration sensor

Capacitance type sensor interface circuit

Interface circuit for capacitive sensor