Micromachined field asymmetric ion mobility filter and detection system
Patent # U.S. 6,495,823 ; Date Issued: December 17, 2002

A micromechanical field asymmetric ion mobility filter for a detection system includes a pair of spaced substrates defining between them a flow path between a sample inlet and an outlet; an ion filter disposed in the path and including a pair of spaced filter electrodes, one electrode associated with each substrate; and an electrical controller for applying a bias voltage and an asymmetric periodic voltage across the ion filter electrodes for controlling the paths of ions through the filter.

Reentrant microwave resonant cavity accelerometer
Patent # U.S. 6,481,286; Date Issued: November 19, 2002

An improved microwave resonant cavity accelerometer includes a reentrant microwave resonant cavity. Preferably, the accelerometer includes first and second complementary reentrant microwave resonant cavities, each being characterized by a nominal resonant frequency. Each cavity includes a capacitive gap, and an inductive gap surrounding each capacitive gap. A coupler couples to each cavity a microwave signal substantially at the nominal resonant frequency of each cavity. In response to an acceleration force along a sensing axis, a proof mass positioned along the sensing axis differentially changes the dimensions of each cavity and establishes a resonant frequency for each cavity which varies as a function of the acceleration force. The accelerometer includes means for detecting electromagnetic energy in each cavity and determining the frequency of the detected energy. The shift in resonant frequency is used to determine the acceleration of the proof mass. By using-reentrant cavities, the sensitivity of the accelerometer to an acceleration of the proof mass is improved by a factor of about 100 for miniaturized proof masses. The accelerometer may be fabricated using micromachining techniques.

Resonator with preferred oscillation mode
Patent # U.S. 6,455,980; Date Issued: September 24, 2002

A resonator with mechanical node reinforcement includes a substrate, an intermediate portion adjacent to the substrate, and a resonant portion adjacent to the intermediate portion. The intermediate portion may include multiple layers, such as an insulating layer and/or a conductive layer. The resonant portion of the resonator is adapted for an oscillation mode with a nodal point located within its periphery. Preferably, the resonant portion contacts the intermediate portion at points located at the periphery and at the nodal point. The resonant portion may include multiple layers and its primary layer may be a membrane or a plate. An alternative embodiment of the resonator excludes the intermediate layer allowing the resonant portion to contact the substrate instead of the intermediate layer.

Drive feedthrough nulling system
Patent # U.S. 6,445,195; Date Issued: September 3, 2002

The present invention relates to a system for nulling drive feedthrough error in a sensor having first and second drive electrodes which impart vibratory motion to first and second proof masses in response to first and second opposite phase drive signals, and having first and second capacitances defined between the drive electrodes and their associated proof masses. A mismatch between the first and the second capacitance is measured. Drive feedthrough caused by the measured capacitance mismatch is nulled by adjusting the relative amplitudes of the first and second opposite phase drive signals, whereby the ratio of the amplitudes is proportional to the ratio of the first and second capacitances. A servo loop may adaptively effect the ratio of amplitudes.

Flyer assembly
Patent # U.S. 6,392,213; Date Issued: May 21, 2002

A flyer assembly is adapted for launching with, transit in, and deployment from an artillery shell having a central void region extending along a ballistic shell axis. The flyer assembly includes a jettisonable shroud and a flyer. The shroud extends along a shroud axis, and is positionable within the central void region with the shroud axis substantially parallel to the shell axis. The flyer is adapted to withstand a launch acceleration force along a flyer axis when in a first state, and to effect aerodynamic flight when in a second state. When in the first state, the flyer is positionable within the shroud with the flyer axis parallel to the shroud axis and the shell axis. The flyer includes a body member disposed about the flyer axis, and a foldable wing assembly mounted to the body member. The wing assembly is configurable in a folded state characterized by a plurality of nested wing segments when the flyer is in the first state. The wing assembly is configurable in an unfolded state characterized by a substantially uninterrupted aerodynamic surface when the flyer is in the second state. The flyer assembly is adapted to be launched from a ballistic delivery system such as an artillery cannon, and can thus reach a target quickly, without expending system energy stored within the flyer. During launch, the flyer is coupled to the shroud so as to maintain a portion of the flyer in tension during an acceleration of the flyer along the flyer axis resulting from the launch. The flyer assembly is adapted to withstand the high g-load and high temperature environments of a cannon launch, and can tolerate a set-back g load of about 16,000 g.

Antijam null steering conformal cylindrical antenna system
Patent # U.S. 6,388,610; Date Issued: May 14, 2002

An antijam null steering conformal cylindrical antenna system includes a cylindrical array of linearly polarized individually weighted antenna elements; a plurality of weighting circuits one associated with each of the elements; and means, responsive to the power output of the weighting circuit, for decreasing the sensitivity in the direction of the maximum incident power.

Multi-axis magnetically actuated device
Patent # U.S. 6,388,789; Date Issued: May 14, 2002

A multi-axis magnetically actuated device, an array of multi-axis magnetically actuated devices, and a method of fabrication of a multi-axis magnetically actuated device are disclosed. In addition, disclosed is an optical switch comprised of an array of multi-axis magnetically actuated devices and an array of ports adapted to receive an optical waveguide such as, for example, an optical fiber. The multi-axis magnetically actuated device of the invention is capable of rotational movement in two orthogonal directions. In one embodiment, the multi-axis magnetically actuated device comprises two nested rotational members, an inner rotational member nested within an outer rotational member that in turn is nested within a base member. The inner rotational member is mounted by two inner torsional flexures to the outer rotational member that in turn is mounted by two outer torsional flexures to the base member. The inner torsional flexures define an inner axis of rotation while the outer torsional flexures define an outer axis of rotation. The rotational motions of each rotational member arise in response to an interaction between a magnetic influence and a magnetic moment generated by a current passing through coils arranged adjacent to a surface of the inner rotational member. Bulk micromachining techniques enable the members to be formed from a monolithic silicon wafer and can produce a member with a smooth surface. The smooth surface of a member may function as a reflector. In one embodiment, the inner rotational member functions as a reflector.

Method of recovering encapsulated die
Patent # U.S. 6,368,886; Date Issued: April 9, 2002

A method of decapsulating a packaged die includes removing packaging material from the bottom section of a die-containing package to expose a die pan, removing the die pan, removing material between the die pan and the bottom surface of the die, using the bottom surface of the die to determine a grind plane substantially parallel to the top surface of the die, and removing packaging material from the top section of the die-containing package to form a top surface substantially planar to the grind plane, preferably intersecting the wire bonds on the face of the die.

Multipath Propagation Detection and Avoidance Method and System
Patent # U.S. 6,362,782; Date Issued: March 26, 2002

Multipath propagation detection can be accomplished using first and second spaced antennas which receive a carrier signal from a moving radiation source and produce a carrier phase difference representative of the location of the source; a difference signal representative of the difference between the measured carrier phase difference and a predetermined phase difference for the source in that location is generated; and the presence of multipath distortion in that difference signal is determined. Furthermore, when a multiplicity of source signals are tracked as in reception of navigation signals from the Global Positioning Satellite System, the receiver may be programmed to eliminate or suppress errors arising from measurements that have been distorted by multipath propagation.