144 results about "Gain-switching" patented technology

In receiver systems for cellular phones using the W-CDMA method, the change in DC voltage occurring when the gain of a programmable gain amplifier (PGA circuit) is switched to adjust the gain for a received signal, can be suppressed. A sample-and-hold circuit is installed containing a “sample” mode for directly outputting a signal from the PGA section and also containing a “hold” mode for outputting the electric charge of a specified voltage stored in a capacitor. This sample-and-hold circuit normally operates in “sample” mode so the output signal from the PGA section is directly output, but is operated in “hold” mode at the gain switching timing of the PGA circuit, so that the electric charge of the specified voltage stored in the capacitor is output for a specified length of time (equal to the time required for the DC voltage change to converge to a stable level).

An energy-efficient method and system for processing target material such as microstructures in a microscopic region without causing undesirable changes in electrical and/or physical characteristics of material surrounding the target material is provided. The system includes a controller for generating a processing control signal and a signal generator for generating a modulated drive waveform based on the processing control signal. The waveform has a sub-nanosecond rise time. The system also includes a gain-switched, pulsed semiconductor seed laser for generating a laser pulse train at a repetition rate. The drive waveform pumps the laser so that each pulse of the pulse train has a predetermined shape. Further, the system includes a laser amplifier for optically amplifying the pulse train to obtain an amplified pulse train without significantly changing the predetermined shape of the pulses. The amplified pulses have little distortion and have substantially the same relative temporal power distribution as the original pulse train from the laser. Each of the amplified pulses has a substantially square temporal power density distribution, a sharp rise time, a pulse duration and a fall time. The system further includes a beam delivery and focusing subsystem for delivering and focusing at least a portion of the amplified pulse train onto the target material. The rise time (less than about 1 ns) is fast enough to efficiently couple laser energy to the target material, the pulse duration (typically 2-10 ns) is sufficient to process the target material, and the fall time (a few ns) is rapid enough to prevent the undesirable changes to the material surrounding the target material.

A digital to analog converter that may include a digital gain block; an analog gain block; a digital to analog conversion (DAC) block and a controller that is configured to: determine a digital gain factor, selected out of multiple digital gain factors, of the digital gain block and an analog gain factor, selected out of multiple analog gain factors of the analog gain block; wherein the DAC block is preceded by the digital gain block and is followed by the analog gain block; wherein the digital gain block is configured to multiply a digital input signal by the digital gain factor to provide an intermediate digital signal; wherein the DAC block is configured to convert the intermediate digital signal to a converted analog signal; and wherein the analog gain block is configured to multiply the converted analog signal by the analog gain factor to provide an output signal; wherein an increment of the analog gain factor results in a decrement of the digital gain factor.

To reduce circuit area and power consumption and suppress transient response occurring at switching in PGA of a programmable gain amplifier is provided a wireless communication receiver comprising PGAs for adjusting the gain of a received signal down-converted by mixers and sending it to base-band block. Within PGAs are provided HPFATT circuits formed of capacitors arranged in series, and ladder resistors arranged in parallel, with signal lines, and a plurality of switches. HPFATT is a circuit serving as a high-pass filter and an attenuator for gain switching, wherein switches are controlled by control signal sg from a controller. Amplifiers connected to the rear stage of the HPFATT circuit are formed of MOS transistors.

This disclosure discusses techniques for obtaining wavelength selected simultaneously super pulsed Q-switched and cavity dumped laser pulses utilizing high optical damage threshold electro-optic modulators, maintaining a zero DC voltage bias on the CdTe electro-optic modulator (EOM) so as to minimize polarization variations depending on the location of the laser beam propagating through the CdSe EOM crystal, as well as the addition of one or more laser amplifiers in a compact package and the use of simultaneous gain switched, Q-switched and cavity dumped operation of CO₂ lasers for generating shorter pulses and higher peak power for the hole drilling, engraving and perforation applications.

A high performance imaging system for diffuse optical tomography is disclosed. A dense grid utilizing sources, e.g., light emitting diodes (“LEDs”), that achieve high performance at high speed with a high dynamic range and low inter-channel crosstalk are complemented by a system of discrete, isolated receivers, e.g., avalanche photodiodes (“APDs”). The source channels have dedicated reconfigurable encoding control signals, and the detector channels have reconfigurable decoding, allowing maximum flexibility and optimal mixtures of frequency and time encoding and decoding. Each detector channel is analyzed by dedicated, isolated, high-bandwidth receiver circuitry so that no channel gain switching is necessary. The resulting improvements to DOT system performance, e.g., increased dynamic range and decreased crosstalk, enable higher density imaging arrays and provide significantly enhanced DOT image quality. A processor can be utilized to provide sophisticated three dimensional modeling as well as noise reduction.

A semiconductor surface emitting optical amplifier chip utilizes a zigzag optical path within an optical amplifier chip. The zigzag optical path couples two or more gain elements. Each individual gain element has a circular aperture and includes a gain region and at least one distributed Bragg reflector. In one implementation the optical amplifier chip includes at least two gain elements that are spaced apart and have a fill factor no greater than 0.5. As a result the total optical gain may be increased. The optical amplifier chip may be operated as a superluminescent LED. Alternately, the optical amplifier chip may be used with external optical elements to form an extended cavity laser. Individual gain elements may be operated in a reverse biased mode to support gain-switching or mode-locking.

An apparatus for processing signals received from an acoustic touch surface comprises an analog input receiving an analog input signal having a signal level. The analog input signal comprises data indicative of a touch location on a touch surface. A plurality of gain elements receive the analog input signal and output gain-adjusted analog signals. A gain selection module selects one of the gain-adjusted analog signals based on the signal level of the analog input signal

An optical pulse source includes a gain-switched semiconductor laser diode. Light from a continuous wave source is opitically coupled into the laser cavity. Light output from the laser cavity passes through an electro-optic amplitude modulator. Synchronized modulating signals are applied to the semiconductor diode and to the amplitude modulator. The source outputs short low-jitter low-pedestal optical pulses and is suitable for use, for example, in a broadband optical network operating at thigh bit rates of 100 Gbit/s or more, or in an optical interconnect.

The present invention detects whether the supply voltage applied to the power supply terminal (3) is used for the dynamic speaker or for the piezoelectric speaker by the power supply voltage detection circuit (10), switches the gain of the amplifier circuit (8) in accordance with the detection result by the gain switching circuit (11) so that the same output power is produced for the same input signal in the respective speaker driving, and amplifies the input signal from the input terminal (5) by the amplifier circuit (8) having the gain to drive a speaker (1) that is connected to the output terminals (6, 7).

A gain-control method and device that enable high-speed gain switching of cascaded programmable gain amplifiers (PGA) without a high-resolution A/D converter is provided. In one example, the gain-control method for cascaded PGAs detects all the input levels of the PGAs, calculates the optimum gains of the PGAs each on the basis of the detection results, and sets the obtained optimum gains of each of the PGAs at one time, whereby high-speed gain switching becomes possible. The gain-control device for cascaded PGAs that implements this gain-control method includes peak hold circuits that retain the input levels of each of the PGAs, a switch group that sequentially switches outputs of the peak hold circuits, an A/D converter that sequentially detects the outputs from the switch group, and a control and operation device that calculates the optimum gains of the PGAs from the detection results by the A/D converter to set the calculated optimum gains simultaneously to each of the PGAs.

A correction LED is provided to illuminate a light receiving sensor array, and a calculation controlling circuit calculates correction values at the respective illuminance levels based on sensor output levels expected at the respective illuminance levels and actual sensor output levels while successively turning the correction LED on at a plurality of illuminance levels whose illuminance ratios are at least known, and corrects a sensor output level by the corresponding correction value to obtain a measurement output at the time of an actual measurement. The discontinuity of an input/output characteristic resulting from the switching of gains of an amplifier for amplifying a photocurrent and the non-linearity caused by the saturation of the photoelectrically converting characteristic of the optical sensor and the exponential characteristics of the optical sensor and the amplifier can be corrected without employing a large-scale construction such as a bench. The non-linearity can be highly precisely and efficiently corrected in a measuring apparatus realized as a spectral luminometer or a spectral calorimeter without requiring a special facility.

A hydraulic control device is provided with a linear solenoid valve, a shift valve, and a controller. The linear solenoid valve has a gain switching chamber which produces a biasing force in a direction to close the linear solenoid valve to switch the gain characteristic of the linear solenoid valve when oil pressure is supplied to the gain switching chamber. The shift valve is configured to be switchable between a supply state in which the output oil pressure from the linear solenoid valve is supplied to the gain switching chamber and a blocked state in which the supply of the output oil pressure is blocked. The controller brings the shift valve into the supply state when a necessary oil pressure of an engagement element is high and into the blocked state when the necessary oil pressure of the engagement element is low.

A gain switch determination circuit (250) uses a first hysteresis characteristic to perform a comparison/determination of a comparison input voltage (Vc) from an inter-stage buffer circuit (230), and a gain switch signal (SEL) based on a result of the comparison/determination is outputted to first and second transimpedance amplifier core circuits (210,220), thereby switching the gains of those core circuits. This eliminates the necessity of using a level hold circuit, which exhibits a slow response, to hold the comparison input voltage so as to perform a gain switch determination. As a result, an instant gain switch determination can be achieved, thereby realizing an instant response to burst data.

The invention relates to a design method for derivative controlling the gain switching ratio of an aerocraft pose dynamics simplified model, which adopts a nonlinear gain switching PD controlling scheme and allows two PD subcontrollers (a rapid PD subcontroller and a heavy damping subcontroller) designed with different parameters and complementary performance cooperatively function by stages according to switching rules designed. Meanwhile, on the basis of the guarantee of stability of an enclosed ring controlling system in the large, the step response of the system with no overshoot is realized, and the adjusting time of the step response is flexibly adjusted to meet the design requirements of rapidity. The technical scheme of the designing method comprises that: a first step, the structure of the enclosed ring controlling system is designed; a second step, a gain switching strategy section is designed; a third step: the gain parameters of two PD subcontrollers are designed; a fourth step: the rapidity of the step response is inspected and adjusted; a fifth step: the stability of an enclosed ring controlling system in the large is validated; a sixth step: the design is finished.

This invention discloses a method to control laser dynamics in a gain-switched fiber laser so as to generate stable, clean pulses in an all-fiber format. The gain-switched fiber laser is suitable as a standalone laser source, and as a pump source for harmonic generation and an optical-parametric-oscillator.

A converter device which is configured by connecting three converter circuits in parallel is provided between a secondary battery serving as a first power supply and a fuel cell serving as a second power supply. A control unit includes a PID control module which controls the converter device by PID control, for executing desired voltage conversion; a module for modifying the number of drive phases which changes the number of drive phases of the converter device in response to an electric power passing through the converter device; and a gain switching module which switches feedback gains in the PID control when the number of drive phases is changed.

The invention relates to the technical field of mobile communication and discloses an automatic gain control method and a device. On the basis of guaranteeing timeliness and cost of automatic gain control, the automatic gain control method and the device are used for improving performance of the automatic gain control. The automatic gain control method comprises the following steps: capturing system configuration information and corresponding characteristics, determining gain switching time of AGC according to the system configuration information and the corresponding characteristics, counting symbol level time-frequency domain metrical information between the current gain switching time and the next gain switching time, the symbol level time frequency domain metrical information comprises frequency domain power Pw of default resource unit location in various symbols and time domain power Psymbol of the various symbols, comparing the symbol level time frequency domain metrical information with an adaptive gain control target value, obtaining a logarithmic domain difference value, and according to the logarithmic domain difference value, completing gain switching of the automatic gain control at the next gain switching time.