United Technologies Corporation

US Government As Represented by the Secretary of the Army

Honeywell G.m.b.h.

Thomas W Grudkowski

Robert N Sacks

Gary K Montress

Donald E Cullen

Thomas M Reeder

Anthony J DeMaria

William J Tanski

James F Black

Meyer Gilden

Arthur D Ballato

Andrzej Peczalski

Gerald Meltz

Frederick J Leonberger

Daniel H Grantham

Richard A Meinzer

James F Detry

Alexander J Shuskus

Sears W Merritt

George A Kilgore

Harry R Wood

Eric W Petraske

David E Grider

Evan C Polley

Philip T Norusis

Glen W Drake

Richard A Courtney

Gilbert L Johnson

Michael A Basic

The present invention is a piezoelectric device fabricated on a semiconductor that also contains electronic circuitry. A cooling device is used to lower the temperature of the resonator. Electronic circuitry can provide feedback to the resonator to compensate for microphonics that occur at low temperatures. Alternatively, piezoelectric materials that can operate at high temperatures can create a high temperature frequency source.

Compound semiconductor monolithic frequency sources and actuators

A fiber optic sensor for magnetic bearings includes a stator 12, a rotor 14, and an optical transmit/receive fiber 50 which propagates transmit light 112 which is launched across a gap 15 between the stator and the rotor and which receives reflected light 114 that is reflected off of the rotor 14 and travels along the fiber 50 as the light 116. The gap 15 distance is determined by the change in intensity of the return light 114. The transmit/receive fiber 50 may be located radially through or longitudinally along the stator 12. The receive light 116 is detected by a photodetector 120 which provides an electrical signal to a control circuit 124 which controls electromagnetic coils 31-34 of the magnetic bearing. Alternatively, two separate fibers may be used for the transmit and receive light. Also, time or wavelength multiplexing may be employed to allow for remote optical source and detection/control of the gap 15 distance. Further, a plurality of such sensors may be used around the gap 15. Also, a temperature sensor may be embedded within the distance sensor. Further, radial and/or axial gaps may be measured.

Fiber optic sensor for magnetic bearings

A novel heterostructure acoustic charge transport (HACT) device is disclosed which displays both electron and hole transport. The device includes a transducer fabricated on a substrate structure that launches surface acoustic waves. An optional reflector is formed in the substrate structure at an end portion adjacent to the transducer for reflecting the surface acoustic waves. Also included is an electrode configured with the transport channel at an end thereof distal to the transducer for generating electrical signal equivalents of the propagating electrode charge. The device makes use of both the conduction band quantum well to transport electrons and the valance band quantum well to transport holes. In this manner the sampling, processing and detection frequencies of the device can be doubled.

Heterostructure acoustic charge transport device having electron and

A monolithic integrated circuit device combines integrated heterostructure acoustic charge transport (HACT) devices and heterostructure insulated gate field effect transistor (HIGFET) devices in a single structure in which the HACT and HIGFET layers are grown in as a contiguous composite heterostructure.

Integrated heterostructure acoustic charge transport (HACT) and

A heterojunction acoustic charge transport device (HACT) having a charge transport channel 39 which is sandwiched between upper and lower charge confinement layers, 14,20, has the charge transport channel 39 made of a Strained Layer Superlattice (SLS) comprising alternating deep-well semiconductor layers 40, that provide a deep quantum well depth, and strain relief layers 42 that provide strain relief to prevent dislocations from occurring due to lattice mismatches between the InGaAs layers within the channel 39 and the charge confinement layers 14,20, thereby allowing the overall thickness of the channel 39 to be at least as wide as conventional HACT devices that use a GaAs channel. The strain relief layers 42 may be narrowly sized to allow tunneling of electrons across the entire channel 39 thereby allowing the charge to move as a single group, or alternatively, widely sized to provide separate isolated channels thereby allowing the charge to move in separate groups. Both embodiments provide increased quantum well depth in the channel 39 over conventional HACT devices.

Increased well depth hact using a strained layer superlattice

A heterojunction acoustic charge transport (HACT) device having a charge transport layer 16 surrounded by upper and lower charge confinement layers 14,30, respectively, and having a cap layer 36 at the outer surface, above the upper confinement layer 30, is provided with a P-N junction to minimize the effects of surface states. An intermediate layer 34 is disposed between the cap layer 36 and upper charge confinement layer 30. The upper confinement layer 30 and intermediate layer 34 are doped with opposite polarities to provide a P-N junction which creates a built-in electric field having sufficient strength to keep mobile charge carriers, transported by a SAW along the charge transport channel, from being trapped by or recombined with surface states at the external interface of the cap layer 36. Alternatively, the intermediate layer is not present and a cap layer 42 is doped to provide one side of the P-N junction.

HACT structure with reduced surface state effects

A HACT device which propagates charge packets 21 along a charge transport channel 17 by a surface acoustic wave (SAW) 14 is provided with an interdigital electrode grid 30 disposed on the upper surface of the HACT, near the charge transport channel 17, having electrodes 30 spaced a distance of one-half wavelength of the SAW. A hold voltage Vh is applied across alternating electrodes to store (i.e., stop and hold) each charge packet. When a charge packet is to be released, the hold voltage Vh is removed and the electrodes 30 are shorted together or alternatively connected through a maximum allowable impedance, thereby allowing each charge packet 21 to be stored and released by the device without having the electrodes 30 absorb the SAW electric fields. Because the electrodes 30 are spaced one-half a SAW wavelength apart, the HACT memory can store each and every charge packet 21, thereby providing a Nyquist bandwidth device. Furthermore, the electrodes 30 are made thin to reduce mechanical absorption of the SAW by the electrodes.

Nyquist frequency bandwidth hact memory

A sampling device operating as a buffer between a first data signal and a relatively slow processing device accepts the input signal and stores samples of it on a SAW traveling past an input electrode. A blocking potential is applied to a set of electrodes to store a set of charge packets with the SAW device. Packets are consecutively released at a slower rate accommodated to the needs of the next processing unit in line, to read out the sampled signal at a modified rate for intentional distortion of the input signal, for slowing the output stored signal rate, or for time reversal of the signal.

Acoustic charge transport memory device

A high speed analog to digital converter system employs a set of ACT devices in parallel to buffer a high speed data sampling rate to the processing rate of the analog to digital converters employed. Vernier control of phase between individual devices is maintained by controlling the speed of propagation of the SAW wave by illumination of the substrate in response to a phase comparison between the SAW and a reference signal.

Act device having optical control of saw velocity

A one-dimensional or two-dimensional transmission mode spatial light modulator (SLM) includes one or more heterojunction acoustic charge transport (HACT) channels 18 with surrounding layers 16,20 vertically adjacent to a multiple quantum well (MQW) region 14, grown above a thick semiconductor substrate 10 thick enough to allow a surface acoustic wave (SAW) to propagate and transparent to the incident light 40. The SAW is injected by a transducer 24, charge is carried to and from the HACT channel 18 by electrodes 32,34,36, and light 40 is applied to a surface 44 perpendicular to the MQW region 14. Each charge packet 19 in the HACT channel 18 invokes an electric field 52 within the MQW region 14 which determines the optical absorption and index-of-refraction thereof, thereby determining the intensity and/or phase of each output light beam 45. Light modulation is achieved by modulating the amount of charge injected.

Thick transparent semiconductor substrate heterojunction acoustic charge

A one-dimensional or two-dimensional transmission mode spatial light modulator (SLM) includes two different mediums, one medium being a semiconductor comprising one or more heterojunction acoustic charge transport (HACT) channels 28 with surrounding layers 26, 30 vertically adjacent to a multiple quantum well (MQW) region 22, and the other being a transparent piezoelectric insulating substrate 10 thick enough to allow a surface acoustic wave (SAW) 13 to propagate therein. The SAW 13 is launched in the substrate 10 by a transducer 12 and generates electric fields which propagate the charge along the HACT channel 28 in the semiconductor medium 18. Electrodes 32, 34, 36 carry charge to and from the HACT channel 28, and light 40 is applied to a surface 44 perpendicular to the MQW region 22. Charge packets 19 in the HACT channel 28 invoke electric fields within the MQW region 22 which determines the optical absorption and/or index-of-refraction thereof, thereby determining the intensity and/or phase of each output light beam 46. Light modulation is achieved by modulating the amount of charge injected and/or the characteristics of the SAW 11. Various different materials for the substrate 10 may be used to provide desired efects.

Dual medium heterojunction acoustic charge transport multiple quantum

A high speed analog to digital converter system employs a set of ACT/HACT devices in parallel to buffer a high speed data sampling rate to the processing rate of the analog to digital converters employed. Calibration is maintained by periodic comparison of the results of the same input data.

Fast A/D converter

A device having at least two channels for holding electron packets receives serial data in a first channel. A blocking potential is applied to a set of electrodes to store a set of charge packets with the device. Packets are transferred to the other channel, manipulated and released to travel to an output port. Manipulation operations include arithmetic operations, logic operations, multiplexing and demultiplexing.

Act device with buffer channel

The surface acoustic wave device which generates two coherent signals from a single input. The inventive device has three interdigital transducers (IDT) spaced upon a single piezoelectric substrate. The central IDT has three sets of interdigital fingers. A power splitter and an amplifier are connected between the central IDT and one of the other IDT's to form a recirculation loop. An input signal burst applied to the central IDT produces two coherent outputs at the remaining IDT and the power splitter.

Saw circuit for generating continuous time-coherent RF carriers

A large bandwidth, tapped delay line (TDL) surface acoustic wave (SAW) adaptive processor arrangement, for processing a plurality of array values employed as tap weights in the TDL device. The weight quantities may be real or complex. In the complex case, no phase quadrature combiner is required as a result of the technique of offsetting the real and imaginary delay lines, or offset launching of the frequency waveforms to be mixed.

Growing community of inventors

Glastonbury, CT, United States of America

Thomas W Grudkowski