Method for fabricating a tunneling sensor with linear force rebalance
Patent # U.S. 5,991,990; Date Issued: November 30, 1999

System and method for automatically executing decisional rules
Patent # U.S. 5,978,786; Date Issued: November 2, 1999

A system and method for automatically evaluating a decisional rule containing a task and a condition which must be fulfilled before the task can be performed and for automatically performing the task when or whenever the condition is fulfilled in which a decisional rule is entered into computing means, parsed, and then processed such that automatic and continuing iterative evaluations of whether the condition is fulfilled are provided until the condition is fulfilled and then the task associated with the decisional rule is automatically performed and whereby further processing is resumed only after the condition is fulfilled.

Micromechanical accelerometer having a peripherally suspended proof mass
Patent # U.S. 5,969,250; Date Issued: October 19, 1999

A monolithic, micromechanical vibrating beam accelerometer with a trimmable resonant frequency is fabricated from a silicon substrate which has been selectively etched to provide a resonant structure suspended over an etched pit. The resonant structure comprises an acceleration sensitive mass and at least two flexible elements having resonant frequencies. Each of the flexible elements is disposed generally collinear with at least one acceleration sensitive axis of the accelerometer. One end of at least one of the flexible elements is attached to a tension relief beam for providing stress relief of tensile forces created during the fabrication process. Mass support beams having a high aspect ratio support the mass over the etched pit while allowing the mass to move freely in the direction collinear with the flexible elements. Also disclosed is a method for fabricating such an accelerometer. Further disclosed is an alternative embodiment of the aforementioned accelerometer characterized by a low profile, and alternative planar processing methods for fabrication of these and other embodiments.

Monolithic micromachined piezoelectric acoustic transducer and transducer array and method of making same
Patent # U.S. 5,956,292; Date Issued: September 21, 1999

A monolithic micromechanical piezoelectric acoustic transducer with integrated control circuit includes a support member; a piezoelectric medium disposed on the support member; first and second electrodes engaging the piezoelectric medium; and a control circuit monolithically integrated with the piezoelectric medium and electrodes on the support member and including a switching circuit for selectively interconnecting the electrodes with an I/O bus and a signal processing circuit for conditioning signals propagating between the electrodes and the I/O bus; an array of such acoustic transducers that form an acoustic retina; and a method of making such transducers and arrays.

Trenches to reduce charging effects and to control out-of-plane sensitivities in tuning fork gyroscopes and other sensors
Patent # U.S. 5,952,574; Date Issued: September 14, 1999

Trenches which reduce or eliminate force and sensitivity associated with proof mass motion normal to the substrate as a result of voltage transients is disclosed. The trenches provide increased separation between interleaved comb electrodes and the substrate, and thereby also reduce the comb lift to drive ratio. The trenches are typically formed directly below the interleaved comb electrodes, but may also be formed below other suspended portions. Trench depth is from 6-10 microns and provides a comb electrode to substrate separation of approximately 8.5-12.5 microns.

Gettering enclosure for a semiconductor device
Patent # U.S. 5,929,515; Date Issued: July 27, 1999

Gettering enclosures for semiconductor packages, comprising an enclosure having a cavity for accommodating a semiconductor device; a gettering chamber (disposed above the semiconductor device) communicating with the cavity, comprising a getter precursor secured to the cavity and spaced from a wall of the cavity, wherein the wall is transparent to laser light so as to allow a beam of laser light to strike the getter precursor and sputter same on the walls of the gettering chamber.

Radio-wave reception system using inertial data in the receiver beamforming operation
Patent # U.S. 5,917,446; Date Issued: June 29, 1999

A receiver system on a mobile host vehicle platform includes an inertial sensor embedded in an antenna groundplane that supports an array of antenna elements. The beamformer within the receiver system determines the beamforming weights by incorporating inertially-generated signals representative of the attitude of the receiver system and location data identifying the location of GPS satellites. As the host vehicle moves, the beamformer generates the appropriate gain pattern based on the inertial data of the current attitude and the GPS location data. The beamformer, in particular, performs a spatial filtering function that is characterized by high-gain profiles in the direction of transmission of selected ones of the GPS terminals, thereby effectively suppressing signals originating from jammers and other sources of RFI.

Split electrode to minimize charge transients, motor amplitude mismatch errors, and sensitivity to vertical translation in tuning fork gyros and other devices
Patent # U.S. 5,911,156 ; Date Issued: June 8, 1999

A micromechanical tuning fork gyroscope having two center electrodes is disclosed. The two center electrodes are excited with bias potentials of opposite polarity. The oppositely biased center electrodes provide electrical symmetry across the gyroscope and thereby reduce charge transients and sensitivity to vertical translation. Currents injected directly into the proof masses are equal and opposite and thus cancel. Motor lift forces acting on the proof masses and interleaved electrodes are equal, and hence the proof masses move in pure translation, thereby reducing in-phase bias. Further, any pure translation normal to the plane of the gyroscope does effect sense axis output signals.

Electrostatic memory micromirror display system
Patent # U.S. 5,903,383; Date Issued: May 11, 1999

An electrostatic memory micromirror display system including an array of electrostatic memory and display assemblies each including a memory and display element having a mirror surface and a conductive medium; a support device for movably mounting the memory and display element; and a set of electrodes including at least first and second electrodes proximate the conductive medium; and means for selectively applying a voltage to the first electrode of predetermined ones of the memory and display assemblies to establish an electrostatic field between the first electrode and the conductive medium to urge the associated display element from a first position toward a second position and for applying a voltage to the second electrode of the assemblies to establish an electric field between the second electrode and the conductive medium to set the memory and display element in the second position.

Guard bands which control out-of-plane sensitivities in tuning fork gyroscopes and other sensors
Patent # U.S.5,892,153; Date Issued: April 6, 1999

Guard bands which reduce or eliminate force and sensitivity associated with proof mass motion normal to the substrate as a result of voltage transients is disclosed. The guard bands are biased to reduce the coupling ratio to zero and thereby enable starting and improved performance. Various configurations of guard bands may be employed including distinct inner and outer guard bands, distinct inner guard bands only, extended sense electrodes below inner sensing combs with no outer guards, distinct outer guard bands with extended sense electrodes, and sense electrodes extended beneath both drive and sensing combs.

Autonomous local vertical determination apparatus and methods for a ballistic body
Patent # U.S. 5,886,257; Date Issued: March 23, 1999

Three rate gyros are mounted to a ballistic body to provide an autonomous navigation system. A roll gyro, a yaw gyro and a pitch gyro are rigidly fixed to the ballistic body. Each gyro is arranged to be responsive to a roll rate about an input axis that is substantially orthogonal to any other gyro. The roll-rate gyro has its input axis aligned parallel to the body spin axis. An on-board processor utilizes recursive Kalman-filtering to determine the roll angle, i.e., the local vertical direction, from the gyro outputs.