48results about How to "Fast rise time" patented technology

Exemplary embodiments of the invention provide a system, method and apparatus for spread spectrum functionality for a free-running, reference harmonic oscillator. In an exemplary embodiment, an apparatus comprises a reference oscillator adapted to provide a reference signal having a reference frequency; and a spread spectrum controller adapted to control the reference oscillator to generate a spread-spectrum reference signal at a plurality of different reference frequencies during a predetermined or selected time period. An exemplary apparatus may also include a coefficient register adapted to store a plurality of coefficients and a plurality of controlled reactance modules responsive to a corresponding coefficient of the plurality of coefficients to modify an amount of reactance effectively coupled to the reference oscillator. An exemplary spread spectrum controller is further adapted to sequentially modify the plurality of coefficients during the predetermined time period to provide the spread spectrum reference signal.

In all-optical networks, high speed optical switching and routing becomes one of the most important issues for interconnecting the transport network layers. This invention describes novel polarization-independent high speed optical switches using a digital Faraday rotator, which can also be used for various other optical switching devices. The basic digital Faraday rotator device is composed of (a) a semi-hard or hard iron garnet based magneto-optic crystal having bi-stable magnetization states at zero external magnetic field. (b) a wire winding around the crystal for changing the magnetization states by pulsed current having both fast rise time and short duration. (c) a circuit generating the required current pulses with both polarities. After a driving current pulse excitation to set the magnetization direction, the high coercive force and high remnant squareness in the garnet-based crystal will maintain the saturation magnetization state in the crystal without the need of any external current or magnetic field to sustain the remnant state. The apparatus and the method disclosed in this invention effectively reduces the overall power consumption. By using this digital Faraday rotator device, the polarization independent 1x2 and 2x2 optical switches are designed and fabricated.

Exemplary embodiments of the invention provide a reference signal generator having a controlled quality (“Q”) factor. An exemplary apparatus to generate a harmonic reference signal includes a reference resonator, such as an LC-tank, which generates a first reference signal having a resonant frequency, and a plurality of reactance modules couplable to the reference resonator. Each reactance module comprises one or more reactance unit cells, and each reactance unit cell comprises a reactance element coupled in series to a switching element. In exemplary embodiments, the reactance element is a capacitor having a predetermined unit of capacitance, and the switching element is a transistor having a predetermined resistance when in an off state. The ratio of capacitance to resistance is substantially constant for all reactance modules of the plurality of reactance modules.

A system and method for producing modulated electrical signals. The system uses a variable resistor having a photoconductive wide bandgap semiconductor material construction whose conduction response to changes in amplitude of incident radiation is substantially linear throughout a non-saturation region to enable operation in non-avalanche mode. The system also includes a modulated radiation source, such as a modulated laser, for producing amplitude-modulated radiation with which to direct upon the variable resistor and modulate its conduction response. A voltage source and an output port, are both operably connected to the variable resistor so that an electrical signal may be produced at the output port by way of the variable resistor, either generated by activation of the variable resistor or propagating through the variable resistor. In this manner, the electrical signal is modulated by the variable resistor so as to have a waveform substantially similar to the amplitude-modulated radiation.

An apparatus and method for disinfestation of temperature sensitive and other commodities using short duration, high peak power radio frequency pulses and intense electric fields to preferentially induce drift of conduction charges, spot heating and other mortal damage to infesting insects and mites without raising the temperature of the host commodity. A low frequency mode is provided with a frequency range of approximately 10 Hz to 1 MHz and is particularly suited for large batch processing of pallets or field containers. A high frequency mode is also provided that is suited for continuous or small batch processing and uses a preferred frequency range of approximately 1 MHz to 150 MHz. Both modes preferably have an electric field strength of greater than approximately 5 kV/cm and pulse repetition rates of between one pulse and approximately 10 million pulses per second. The method is non-contact, residue free and effective with all biological stages of an infesting insect, mite or other biological pest including egg, pupa, larvae, juvenile and adult forms. The apparatus and methods of the invention are an effective alternative to methyl bromide fumigation that does not leave any toxic residues or damage the cosmetic appearance or flavor of the commodity.

Exemplary embodiments of the invention provide a reference signal generator, system and method. An exemplary apparatus to generate a harmonic reference signal includes a reference resonator, such as an LC-tank, and a common mode controller. The reference resonator generates a first reference signal having a resonant frequency, and the common mode controller maintains substantially constant a common mode voltage level of the reference resonator. An amplitude controller may also be included to maintain substantially constant a magnitude of a peak amplitude of the first reference signal. A temperature-dependent control voltage also may be generated and utilized to maintain the resonant frequency substantially constant or within a predetermined variance of a calibrated or selected frequency.

An apparatus to deliver air to a patient through a mask, including an air blower (33) where the impeller (5) is rotated by an electromotor including a rotor (3) and a stator (8), the stator having at least three sectors (8a, 8b and 8c), the rotation of the rotor being enabled by changes of the polarity of the sectors, each sector's polarity configuration constituting one step of the rotor's rotation, the apparatus including a driving unit (36) changing the sectors' polarity when the rotor is at its optimal position, so that the efficiency of the electromotor enables the blower to have fast accelerations and decelerations within one patient's breath step, the breath step consisting of one inspiration and one expiration.

A composite battery set, including a metal-ceramic ruthenium-oxide ultracapacitor and a secondary lithium-ion battery, is provided. The composite battery set is electrically connected to an electrical device, which cuts down the total impedance by the metal-ceramic ruthenium-oxide ultracapacitor to increase the output power and the current. The composite battery set is also able to react a pulse rise time less than 5 ms, to speed up the signal react time of the electronic device. And the composite battery set further includes a protective circuit module (PCM) to protect the secondary lithium-ion battery so as to extend the service life and lifespan.

The present invention concerns scintillator compositions comprising gadolinium halide and a dopant. The gadolinium halide and dopant material (e.g., GdI₃:Ce) has surprisingly good characteristics including high light output, high gamma-ray stopping efficiency, fast response, low cost, good proportionality, and minimal afterglow, thereby making the material useful for various applications including, for example, gamma-ray spectroscopy, medical imaging, nuclear and high energy physics research, diffraction, non-destructive testing, nuclear treaty verification and safeguards, and geological exploration. The timing resolution of the scintillators of the present invention also provides compositions suitable for use in imaging applications, such as positron emission tomography (e.g., time-of-flight PET) and CT imaging.

An electronic logic driver circuit, for driving a capacitive load between supply potentials for example for use in driving logic circuit elements on or off a chip, is disclosed. The driver circuit comprises switching devices to switch current either to or from two main voltage supply sources and two coupled inductors that act to store energy derived from the voltage sources. In operation, the coupled inductors form an LC resonator with the load such that energy stored in the inductors can be transferred to or from the load to drive a change in the voltage of the load.

A radar sensor is described that includes a radar transmitter, a radar receiver configured to receive reflected returns of signals output by the radar transmitter, and a signal processing unit configured to process signals received by the radar receiver. The signal processing unit includes a comparator, a first filter comprising an output coupled to a reference input of the comparator, and a second filter comprising an output coupled to a signal input of the comparator. The first and second filters are configured to receive a common input related to the reflected returns. The first filter is configured to have a time constant such that a rise time of the first filter output is faster than a rise time of the second filter output.

The present invention provides a novel PHA comprising a unit containing thioether with high reactivity, and its production method. The present invention also provides polyhydroxyalkanoate (PHA) comprising units having defined chemical formulas (1) and (2), and at least one of four units having defined chemical formulas (3), (4), (5) and (6); its production method; a charge control agent containing the PHA; a toner binder containing the charge control agent; an electrostatic latent image developing toner; and an image forming method and an image forming apparatus using the electrostatic latent image developing toner.

A burst optical signal transmission device which includes a light source for generating and outputting burst signal light, a light source driving circuit for outputting, to the light source, a driving signal for switching between an output time and a stop time of the burst signal light, based on a burst control signal, and a pre-emphasis circuit for outputting a pre-emphasis control signal for superimposing an additional signal for charging a capacitor included in the light source, onto the driving signal, at a timing in the vicinity of the beginning of the burst control signal.

Narrow pulses transmitted wirelessly from a transmitting antenna to a receiving antenna are used to measure the electrical permittivity of the medium of interest between the two antennas. Timing signals are transmitted along a shielded transmission line coincident with the wireless transmission through the medium. The received waveform is digitized in the time domain and analyzed to determine the propagation time. The effects of dispersion caused by the conductive and dielectric properties of the medium on the transmitted waveform are overcome through analysis of the digitized waveform, resulting in an accurate measurement of the propagation time and thus the permittivity of the medium, from which volumetric moisture content may be derived.