Abstract: A direct digital frequency synthesizer having a multi-modulus divider, a numerically controlled oscillator and a programmable delay generator. The multi-modulus divider receives an input clock having an input pulse frequency fosc and outputs some integer fraction of those pulses at an instantaneous frequency fVp that is some integer fraction (1/P) of the input frequency. The multi-modulus divider selects between at least two ratios of P(1/P or 1/P+1) in response to a signal from the numerically controlled oscillator. The numerically controlled oscillator receives a value which is the accumulator increment (i.e. the number of divided pulse edges) required before an overflow occurs that causes the multi-modulus divider to change divider ratios in response to receiving an overflow signal.

Abstract: A tunable acoustic resonator device. The device has a piezoelectric medium as a first thin film layer and a tunable crystal medium as a second thin film layer. The tunable crystal medium has a first acoustic behavior over an operating temperature range under a condition of relatively low applied stress and a second acoustic behavior under a condition of relatively high applied stress. The acoustic behaviors are substantially different. The tunable crystal medium has a highly field-polarizable and lattice-deformable, substantially centrosymmetric structure over an operating temperature range under a condition of relatively low applied stress. The tunable crystal medium has a substantially non-centrosymmetric structure over said operating temperature range under a condition of relatively high applied stress. The dielectric permittivity of the tunable crystal medium is at least 100 at the relatively low applied stress.

Abstract: This invention comprises a process for fabricating a micro mechanical structure in a sealed cavity having a multi-layer high stiffness cap. The high stiffness material used for the cap protects the underlying microstructure from destructive environmental forces inherent in the packaging process and from environmental damage.

Abstract: This invention comprises a process for fabricating a MEMS microstructure in a sealed cavity wherein the etchant entry holes are created as a by-product of the fabrication process without an additional step to etch holes in the cap layer. The process involves extending the layers of sacrificial material past the horizontal boundaries of the cap layer. The cap layer is supported by pillars formed by a deposition in holes etched through the sacrificial layers, and the etchant entry holes are formed when the excess sacrificial material is etched away, leaving voids between the pillars supporting the cap.

Abstract: In a method of automatically sizing and biasing a circuit, a database is provided including a plurality of records related to cells that can be utilized to form an integrated circuit. A cell parameter of a cell for a circuit is selected and compared to cell parameters residing in the records stored in the database. One record in the database is selected based upon this comparison and a performance characteristic of the circuit is determined from this record.

Abstract: The disclosed fabrication methodology addresses the problem of creating low-cost micro-electro-mechanical devices and systems, and, in particular, addresses the problem of delicate microstructures being damaged by the surface tension created as a wet etchant evaporates. This disclosure demonstrates a method for employing a dry plasma etch process to release encapsulated microelectromechanical components.

Abstract: This invention discloses a method for controlling the position of flexible portions of a mechanical structure by attaching one or more Momentum Transfer Actuators on the flexible portions of the mechanical structure near the points whose position is to be controlled, sensing the position of the flexible portions of the mechanical structure, and, employing one or more feedback loops, to control the Momentum Transfer Actuators to cause the flexible ends of the mechanical structure to follow a desired position as a function of time. The invention also addresses the use of combined actuating and sensing devices that incorporate both a Momentum Transfer Actuator and an inertial sensor to provide acceleration, velocity, and position information to the feedback control system.

Abstract: This invention comprises a process for fabricating a micro mechanical structure in a sealed cavity having a multi-layer high stiffness cap. The high stiffness material used for the cap protects the underlying microstructure from destructive environmental forces inherent in the packaging process and from environmental damage.

Abstract: This invention comprises a process for fabricating a micro mechanical structure in a sealed cavity having a multi-layer high strength cap. The high strength material used for the cap protects the underlying microstructure from destructive environmental forces inherent in the packaging process and from environmental damage.

Abstract: This invention discloses a method for facilitating the writing of sector servo marks on disk drives that makes use of an inertial sensor mounted on the positioning arm of the disk drive. In addition, this patent discloses several operating strategies that enhance the accuracy of the inertial sensor when it is used to write sector servo marks.

Abstract: This invention comprises a process for fabricating a MEMS microstructure in a sealed cavity wherein the etchant entry holes are created as a by-product of the fabrication process without an additional step to etch holes in the cap layer. The process involves extending the layers of sacrificial material past the horizontal boundaries of the cap layer. The cap layer is supported by pillars formed by a deposition in holes etched through the sacrificial layers, and the etchant entry holes are formed when the excess sacrificial material is etched away, leaving voids between the pillars supporting the cap.

Abstract: This invention discloses a method for electronically decreasing the sensitivity of thin film movable micromachined layers to vibrations, accelerations, or rotations that would result in part or all of the movable layer being displaced in the direction of the film thickness. In addition, the disclosed method can also be used to remove some of the curvature introduced into thin film movable structures due to vertical stress gradients. Electronic stiffening is achieved by using position sensing and force feedback at one or more points on the movable micromachined structure. Precise servo control of Z axis height makes it possible to dramatically decrease the spacing between the movable MEMS layer or layers and fixed electrodes, which can lead to a dramatic increase in sensitivity and/or actuation force.

Abstract: In a method of automatically sizing and biasing a circuit, a database is provided including a plurality of records related to cells that can be utilized to form an integrated circuit. A cell parameter of a cell that comprises a circuit is selected and compared to cell parameters residing in the records stored in the database. One record in the database is selected based upon this comparison and a performance characteristic of the circuit is determined from this record.

Abstract: This invention discloses a method for controlling the position of flexible portions of a mechanical structure by attaching one or more Momentum Transfer Actuators on the flexible portions of the mechanical structure near the points whose position is to be controlled, sensing the position of the flexible portions of the mechanical structure, and, employing one or more feedback loops, to control the Momentum Transfer Actuators to cause the flexible ends of the mechanical structure to follow a desired position as a function of time. The invention also addresses the use of combined actuating and sensing devices that incorporate both a Momentum Transfer Actuator and an inertial sensor to provide acceleration, velocity, and position information to the feedback control system.

Abstract: A multiple power supply circuit architecture, such as a circuit power system including a first voltage rail, a first reference rail, a second voltage rail, a second reference rail, and a first selective connector between the first and second voltage rails.

Abstract: The present invention is directed to a process for fabricating a microelectromechanical device from a substrate carrying at least one layer of a non-erodible material laid out to form at least a portion of the microelectromechanical device, at least one layer of an erodible material, and at least one sacrificial layer. The process includes the step of using the layer of non-erodible material as a mask and anistropically etching any of the layer of erodible material not occluded by the layer of non-erodible material. The process also includes the step of isotropically etching the sacrificial layer under at least a beam portion of the microelectromechanical device to free the beam portion of the microelectromechanical device from the substrate.

Abstract: The present invention is directed to a detector circuit for detecting a binary data sequence from an input sequence of data. The detector circuit comprises a storage device for storing a plurality of values which correspond to the squared errors computed between all possible input values to the circuit and all possible noiseless responses. The storage device outputs certain of the stored values in response to the input sequence of data. The detector circuit also comprises a Viterbi circuit responsive to the storage device. The Viterbi circuit computes a binary decision output from the outputted stored values. The present invention is also directed to a method for detecting a binary data sequence from an input sequence of data.

Abstract: A circuit architecture is disclosed wherein power is supplied to a CMOS circuit through a first pair of voltage rails, including a first voltage rail (12) providing a first voltage and a second voltage rail (14) providing a second voltage, and a second pair of voltage rails, including a third voltage rail (16) providing a third voltage and a fourth voltage rail (18) providing a fourth voltage. Components (20, 22) comprising two circuit portions are connected across either the first or second pair of voltage rails. The voltage difference across each pair of voltage rails is less than the threshold voltage of the groups of component (20, 22) so that very little current is drawn. Because the voltage offset between the first and second pairs of rails is greater than the threshold voltage of the groups of components (20, 22), sufficient voltage is provided for switching.

Abstract: A microelectromechanical device is comprised of a cantilevered beam positioned above, and free to move relative to, a substrate. The beam may carry a plurality of conductors which are insulated from one another. One or more tips is positioned on the beam with each tip being in electrical contact with one of the conductors. A memory device may be constructed by providing an array of such cantilevered beams proximate to a layer of media. Devices for positioning the beam in x and y directions perpendicular to each other and parallel to the layer of media and in a z direction perpendicular to the media are provided. A control circuit generates control signals input to the positioning devices for positioning the tips according to x, y, and z coordinates.

Abstract: A high speed sample and hold circuit comprises an amplifier for producing an output current which is a linear function of an input voltage. A capacitor is responsive to the output current for producing an output voltage representative of the integral of the output current over a predetermined period of time. A switch selectively connects the amplifier to the capacitor during the predetermined period of time. A circuit for discharging the capacitor is also provided. A circuit for producing clock pulses controls the operation of the switch and the discharge circuit. A finite impulse response filter may be constructed around the sample and hold circuit.