Abstract: A system for discerning an audible command from ambient noise in a vehicular cabin is disclosed. The system comprises a microphone array and a signal processing system.

Abstract: Multiple embodiments of a solid state condenser transducer, and methods of manufacture, are disclosed. The transducer comprises a semi-conductor substrate forming a frame and having an opening, a thin-film cantilever structure forming a diaphragm extending over a portion of the opening, the structure having a proximal portion and a distal portion. The proximal portion is attached to the frame, and the distal portion extends over a portion of the frame. A variable gap capacitor having a movable plate and a fixed plate is provided, wherein the movable plate is disposed on the distal portion of the structure and the fixed plate is disposed on the frame adjacent the movable plate.

Abstract: An impedance matching, reducing, or buffering circuit for permitting smooth signal flow from a first transmission medium to a second transmission medium. The circuit provides a first node adapted for coupling to the first transmission medium and for receiving a signal from the first transmission medium. The circuit further provides a buried channel transistor, that is coupled to the first node and that is biased by additional circuit devices, for transforming the impedance imposed on the signal. The use of the buried mode transistor reduces noise on the surface of the transistor while at the same time keeps other performance standards high. The circuit additionally provides a second node that is coupled to the buried channel transistor and that is adapted for coupling to the second transmission medium for conveying the signal to the second transmission medium.

Abstract: A housing for shielding a transducer of the type mounted on a silicon die attached to a flexible circuit. The housing provides a jacket which protects the silicon die from physical damage. The jacket, in cooperation with the top and bottom cups, further provides a shield for the silicon die from light and electromagnetic interferences. An acoustic port located on the top portion of the jacket furnishes the means by which acoustic energy enters the jacket to contact the transducer. A back cavity, formed between the bottom cup and the silicon die, serves as the acoustic pressure reference which allows the microphone to function properly.

Abstract: A solid state miniature condenser and condenser microphone of good sensitivity is disclosed. The microphone comprises a fixed perforated backplate that constitutes a fixed electrode in a parallel plate condenser, a diaphragm sensitive to incident sound pressure waves that constitutes a moveable plate in the parallel plate condenser, keepers to position the diaphragm in relationship to the backplate without applying appreciable tension to the diaphragm, and FET circuitry which provides an output proportional to the change in capacitance of the condenser when the diaphragm moves in relationship to the backplate.

Abstract: An impedance matching, reducing, or buffering circuit for permitting smooth signal flow from a first transmission medium to a second transmission medium. The circuit provides a first node adapted for coupling to the first transmission medium and for receiving a signal from the first transmission medium. The circuit further provides a buried channel transistor, that is coupled to the first node and that is biased by additional circuit devices, for transforming the impedance imposed on the signal. The use of the buried mode transistor reduces noise on the surface of the transistor while at the same time keeps other performance standards high. The circuit additionally provides a second node that is coupled to the buried channel transistor and that is adapted for coupling to the second transmission medium for conveying the signal to the second transmission medium.

Abstract: An improved diaphragm sensor employs silicon-on-silicon technology and has monolithic integrated signal conditioning circuitry. The support circuitry minimizes the effects of stray capacitance and may be configured to provide either analog or digital output to external terminals. It has a wide band of linearity and is particularly useful for accurately measuring pressures less than 0.5 PSI. The sensor is constructed by joining a silicon top plate having a mechanical pressure stop, a reduced thickness silicon diaphragm and a back plate having CMOS circuitry thereon. These components are bonded together by eutectic soldering.

Abstract: An optoelectronic system for measuring at least one property of an environment includes a first light source for generating light at a first wavelength, first feedback means coupled to the first light source for maintaining the light from the first light source at a substantially constant level, a second light source for generating light at a second wavelength, second feedback means coupled to the second light source for maintaining the light from the second light source at a substantially constant level, a sensor to be placed in an environment, the sensor being responsive to a change in a property of an environment, the sensor generating first and second optical output signals representing a change in the light from the first and second light sources, respectively, due to a property of the environment, an optical waveguide for transmitting light from the first and second light sources to the sensor, a detector for detecting the first and second optical output signals, an optical waveguide for transmitting th

Abstract: A decoder for recovering data signals and clock signals from an encoded data stream includes: a delay circuit responsive to an encoded data stream for producing a delayed data stream, the delayed data stream being delayed a predetermined period of time from the encoded data stream; a D-type flip-flop responsive to the encoded data stream and to a clock signal for producing a data signal; and a phase comparator responsive to the delayed data stream and to the data signal for producing a clock signal.

Abstract: A chemically sensitive device for monitoring chemical properties is described. The device includes a depletion-mode field-effect transistor. Two electrical leads are connected between source and drain region of the field-effect transistor to monitor changes in current or potential resulting from changes in the amount of chemical to be monitored. A reference electrode is attached to a lower substrate surface of the field-effect transistor and electrically connected to the source via a highly doped region adjacent to the source and another highly doped region adjacent to the reference electrode, both having a polarity identical to the substrate. A sensing membrane which is specific to the chemical to be monitored is located on a portion of the substrate remote from the gate region but electrically connected to the gate region to alter conductance between the source and the drain in accordance with the presence or absence of the chemical to be monitored.