Abstract: Provided are a traveling wave tube and a high-frequency circuit system such that the product life span of the traveling wave tube operating in multiple modes can be extended while variations in gain and amplification efficiency that accompany switching of the operation modes can be suppressed. The traveling wave tube comprises: an electron gun equipped with a cathode that releases electrons, and a heater that provides the cathode with heat energy for releasing the electrons; a helix causing an RF signal to interact with an electron beam formed from the electrons released by the electron gun; a collector for catching the electron beam emitted by the helix; an anode whereby the electrons released from the electron gun are guided into the helix; and a magnetic field application device for generating a magnetic field in order to change the diameter of the electron beam, said magnetic field application device being supplied with electric power for generating the magnetic field from the outside.

Abstract: A semiconductor structure, such as a group III nitride-based semiconductor structure is provided. The semiconductor structure includes a cavity containing semiconductor layer. The cavity containing semiconductor layer can have a thickness greater than two monolayers and a multiple cavities. The cavities can have a characteristic size of at least one nanometer and a characteristic separation of at least five nanometers.

Abstract: An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The p-type contact layer and electron blocking layer can be doped with a p-type dopant. The dopant concentration for the electron blocking layer can be at most ten percent the dopant concentration of the p-type contact layer. A method of designing such a heterostructure is also described.

Abstract: Sensors incorporating piezoresistive materials are described. One class of sensors includes piezoresistive material that is held or otherwise supported adjacent conductive traces on a substrate. Another class of sensors includes conductive traces formed directly on the piezoresistive material. Two-dimensional sensor arrays incorporating piezoresistive materials are also described.

Abstract: Some embodiments include an electrochemical sensor. The electrochemical sensor has a lid element comprising a substrate, multiple electrodes, multiple interior contacts electrically coupled to the multiple electrodes, a base element configured to be coupled to the lid element, and an electrolyte element. The base element includes a sensor cavity, multiple exterior contacts located at an exterior surface of the base element, and multiple signal communication channels comprising multiple signal communication lines, and the electrolyte element is located in the sensor cavity. When the lid element is coupled to the base element, the multiple electrodes are located in the sensor cavity, the multiple electrodes are in electrolytic communication with the electrolyte element, the multiple interior contacts are located in the sensor cavity, and the multiple interior contacts are electrically coupled to the multiple exterior contacts by the multiple signal communication lines.

Abstract: A traveling wave tube system includes a traveling wave tube, and a power supply device for supplying required power supply voltages to the respective electrodes of the traveling wave tube. The power supply device includes a control voltage generation circuit for generating a control voltage which is a negative DC voltage on the basis of a ground potential and supplying the control voltage to the anode, an anode voltage generation circuit for generating an anode voltage which is a negative DC voltage on the basis of the potential of the anode and supplying the anode voltage to the cathode, and a collector voltage generation circuit for generating a collector voltage which is a positive DC voltage on the basis of the potential of the cathode and supplying the collector voltage to the collector.

Abstract: A circuit including a semiconductor device having a set of space-charge control electrodes is provided. The set of space-charge control electrodes is located between a first terminal, such as a gate or a cathode, and a second terminal, such as a drain or an anode, of the device. The circuit includes a biasing network, which supplies an individual bias voltage to each of the set of space-charge control electrodes. The bias voltage for each space-charge control electrode can be: selected based on the bias voltages of each of the terminals and a location of the space-charge control electrode relative to the terminals and/or configured to deplete a region of the channel under the corresponding space-charge control electrode at an operating voltage applied to the second terminal.

Abstract: An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The p-type contact layer and electron blocking layer can be doped with a p-type dopant. The dopant concentration for the electron blocking layer can be at most ten percent the dopant concentration of the p-type contact layer. A method of designing such a heterostructure is also described.

Abstract: The current invention introduces a modulated field element incorporated into the semiconductor device outside the controlling electrode and active areas. This element changes its conductivity and/or dielectric properties depending on the electrical potentials of the interface or interfaces between the modulated field element and the semiconductor device and/or incident electromagnetic radiation. The element is either connected to only one terminal of the semiconductor device, or not connected to any terminal of a semiconductor device nor to its active area(s). Such an element can be used as modulated field plate, or a part of a field plate, as a passivation layer or its part, as a guard ring or its part, as a smart field or charge control element or its part, as a feedback element or its part, as a sensor element or its part, as an additional electrode or its part, as an electromagnetic signal path or its part, and/or for any other functions optimizing or modernizing device performance.

Abstract: A device and method for improved geodetic and seismic measurements are disclosed. The device comprises a triaxial accelerometer assembly, mounted to a reference structure, having full scale ranges greater than +/?1 G on three orthogonal axes and a mechanism for rotating the triaxial accelerometer assembly on the reference structure. The triaxial acceleration assembly is calibrated with an internal alignment matrix such that measurements of Earth's gravity vector are rotationally invariant with respect to the direction of Earth's 1 G static gravity vector irrespective of the orientation of the triaxial assembly on the reference structure. In-situ calibrations are performed by rotating the axes of the triaxial acceleration assembly in the direction of Earth's static gravity vector. Drift of the triaxial accelerometer assembly is compensated for by measuring changes in the values of the invariant static gravity vector for each axis and correcting for the drift with new calibration coefficients.

Abstract: A composite substrate configured for epitaxial growth of a semiconductor layer thereon is provided. The composite substrate includes multiple substrate layers formed of different materials having different thermal expansion coefficients. The thermal expansion coefficient of the material of the semiconductor layer can be between the thermal coefficients of the substrate layer materials. The composite substrate can have a composite thermal expansion coefficient configured to reduce an amount of tensile stress within the semiconductor layer at room temperature and/or an operating temperature for a device fabricated using the heterostructure.

Abstract: A control moment gyroscope (CMG) module for use in a satellite comprising a CMG, the CMG comprising a flywheel assembly mounted on a gimbal assembly, the flywheel assembly comprising a flywheel rim, a flywheel spokes member and a flywheel shaft, the flywheel rim circumscribing the flywheel shaft, and the flywheel spokes member extending between the flywheel shaft and the flywheel rim. The gimbal assembly comprises at least one gimbal and a spin motor, the spin motor for rotating the flywheel assembly about a first axis. The CMG further comprises a torque shaft and a torque motor for rotating the at least one gimbal about a second axis. The CMG module further comprises a hermetic first shell housing; and a hermetic second shell housing; wherein the second shell housing is joined to the first shell housing by a hermetic seal to form an airtight interior of the CMG module, the interior of the CMG module containing the CMG.

Abstract: An approach for preparing a vaccine using ultraviolet radiation is described. Aspects of this approach involve multiple iterations of inactivation of the vaccine using an ultraviolet radiation source at a set of different wavelengths and dosages. A recognition test of the vaccine using the set of different wavelengths and dosages is performed after the multiple iterations of inactivation. A controller compares results from the inactivation test and the recognition test to determine an area of acceptable radiation dosages and wavelengths generated from the ultraviolet radiation source that irradiate the live organisms without affecting efficacy and safety of the vaccine. The area of acceptable ultraviolet radiation dosages and wavelengths is representative of a difference between an ultraviolet radiation dosage that is required for inactivation and an ultraviolet radiation dosage that leads to a loss of recognition.

Abstract: The present invention relates to a gas sensor comprising a sensor layer (100) comprising a plasmonic sensor (102) provided so as to allow, upon illumination with electromagnetic radiation a localized surface plasmon resonance condition, a sensing layer (106) comprising a gas permeable material that, when exposed to a gas, modifies the localized surface plasmon resonance condition, a separating layer (104) arranged in between the sensor layer (100) and the sensing layer (106) such that the plasmonic sensor (102) is separated from the sensing layer (106). A gas sensing system and a method for sensing a presence of a gas is further disclosed.

Abstract: The method and apparatus as shown in the present invention is to measure the absorption of light by material contained in a liquid. A transmitted signal is sent through a measurement window to a measurement chamber to a target point just inside the measurement window. The reflected signal indicates the amount of light absorbed by a material in the measurement chamber which allows for the amount of materials in a liquid to be determined. Adjustments are made through an optical block and a light control molecule to correct for variations in light intensity.

Abstract: An angle sensor is disclosed. The angle sensor has a disc, a first magnetic pattern disposed on a side of the disc and including a number N1 of first portions of spirals regularly distributed in a first ring, and a second magnetic pattern disposed on a side of the disc and including a number N2 of second portions of spirals regularly distributed in a second ring. The numbers N1 and N2 are coprime and N1 is different from N2, N2?1, and N2+1.

Abstract: A heterostructure for use in an electronic or optoelectronic device is provided. The heterostructure includes one or more semiconductor layers containing columnar nanostructures (e.g., nanowires). The nanowire semiconductor layer can include sub-layers of varying composition, at least one of which is an active layer that can include quantum wells and barriers. A heterostructure can include n-type and p-type semiconductor contact layers adjacent to the nanowire semiconductor layer containing the active layer.

Abstract: A mechanical scanning system for the illuminating laser beam and return light in LIDAR imaging systems. The scanning system includes a flat mirror having reciprocating rotary motion around a horizontal axis for vertical scan of the illuminating laser beam and return light. The reciprocating rotary motion of the mirror is driven by a continuously rotating motor, a cam mounted on the motor and a follower connected to the mirror and driven by the cam. An encoder is connected to the minor's shaft and provides position indication to the imaging control electronics.

Abstract: An optoelectronic device configured for improved light extraction through a region of the device other than the substrate is described. A group III nitride semiconductor layer of a first polarity is located on the substrate and an active region can be located on the group III nitride semiconductor layer. A group III nitride semiconductor layer of a second polarity, different from the first polarity, can located adjacent to the active region. A first contact can directly contact the group III nitride semiconductor layer of the first polarity and a second contact can directly contact the group III nitride semiconductor layer of the second polarity. Each of the first and second contacts can include a plurality of openings extending entirely there through and the first and second contacts can form a photonic crystal structure. Some or all of the group III nitride semiconductor layers can be located in nanostructures.

Abstract: The present invention relates to a battery (100) comprising an electrode material (102a), an electrolyte material (104), a battery charge sensor (106, 206, 306) comprising a plasmonic sensing element (108, 208, 308) having a sensing volume (110, 210, 310) within the battery (100, 200, 401) and which upon illumination with electromagnetic radiation exhibits a localized surface plasmon resonance condition being dependent on a charge state of the battery (100, 200, 401). A system and a method for determining a charge state of a battery are further provided.