36 results about "Amplifier noise" patented technology

An RNG circuit is connected to the parallel port of a computer. The circuit includes a flat source of white noise and a CMOS amplifier circuit compensated in the high frequency range. A low-frequency cut-off is selected to maintain high band-width yet eliminate the 1/f amplifier noise tail. A CMOS comparator with a 10 nanosecond rise time converts the analog signal to a binary one. A shift register converts the serial signal to a 4-bit parallel one at a sample rate selected at the knee of the serial dependence curve. Two levels of XOR defect correction produce a BRS at 20 kHZ, which is converted to a 4-bit parallel word, latched and buffered. The entire circuit is powered from the data pins of the parallel port. A device driver interface in the computer operates the RNG. The randomness defects with various levels of correction and sample rates are calculated and the RNG is optimized before manufacture.

A method of Raman detection for a portable, integrated spectrometer instrument includes directing Raman scattered photons by a sample to an avalanche photodiode (APD), the APD configured to generate an output signal responsive to the intensity of the Raman scattered photons incident thereon. The output signal of the APD is amplified and passed through a discriminator so as to reject at least one or more of amplifier noise and dark noise. A number of discrete output pulses within a set operational range of the discriminator is counted so as to determine a number of photons detected by the APD.

A lidar three-dimensional imaging system based on a virtual instrument comprises a three-dimensional scene modeling module, a lidar testing system simulation environment modeling module, a full-waveform signal processing module and a three-dimensional reconstruction module. The three-dimensional scene modeling module comprises a three-dimensional model loading element used for setting background colors, visual angle control, illumination, a projection mode, a display model and other basic scene projects. The lidar testing system simulation environment modeling module comprises four modeling sub-modules which are a laser pulse model, an atmospheric transmission model, an object interaction model and a receiving unit model. The laser pulse model is used for simulating a laser source according to the wavelength, pulse width, energy and other characteristics of a laser. The atmospheric transmission model is used for simulating a tested atmospheric environment, so that a noise model is generated for acting on the laser. The object interaction model is used for simulating effects of the laser and a detected object, and the effects comprise mirror reflection, diffuse reflection, surface reflection and speckles. The receiving unit model is used for simulating detector noise and amplifier noise which are generated after sensing.

The invention discloses a noise suppression method for class D power amplifier, which includes a step S1 and a step S2; wherein, in step S1, an external enabling signal is received; in step S2, when the state of external enabling signal is changed, an enabling signal for a class D power amplifier is generated according to the external enabling signal; meanwhile, a silencing signal used for controlling the load of a class D power amplifier is generated according to the external enabling signal. The noise suppression method for class D power amplifier can effectively suppress POP or CLICK noise generated in capacitor charge-discharge process without increasing or modifying chip pins.

The invention relates to a high resolution X radial image amplifier, it includes input window, photoelectricity cathode, micro channel board module, output window and shell; output window includes in turn axial connected fluorescent screen, luminous powder level and aluminum membrane; the shell includes seal ring, the ceramic shell and the output window metal shell; the output window seal fixes in the output window metal shell; the input window seal fixes in the metal window of the middle of seal ring front end; the input window material is the aluminum or beryllium metal, the material of seal ring ia the cut down alloy 4J33, the input window connect seal ring with the aluminum braze welding. This invention solved the technical problem of the existing X radial image amplifier to X radial low transmissibility, the difference contrast gradient, the serious scattering, the big noise; the invention has high transmissibility and the small scattering power to X radial, can reduced electronic dissemination time, the transit time and the space charge effect, reduced X radial image amplifier noise, enhanced the contrast gradient.

An amplifier (10) includes a first stage (4) including differentially coupled first (Q1) and second (Q2) input transistors and a controlled active load circuit (6). A second stage (8) includes differentially coupled third (Q5) and fourth (Q6) input transistors and a load circuit (Q7,8). A first output (2A) of the first stage (4) is coupled to a first input of the second stage (8), a second output (2B) of the first stage (4) being coupled to a second input of the second stage (8). A common mode feedback amplifier (12) has an input coupled to receive a common mode signal (3) from the second stage (8) for producing an amplified common mode signal (9) on a control input of the controlled active load circuit (6) to provide fast settling of an output (Vout) of the second stage without substantially increasing amplifier noise.

An extended dynamic range optical amplifier, a method of operation, and a line amplifier configuration include an optical amplifier that can be optimized for high or low span loss conditions by switching an internal stage in or out of an internal light path within the amplifier. The extended dynamic range optical amplifier can include a low gain mode and a high gain mode with an internal switch to switch out a gain mid-stage in a low gain mode to extend the useful dynamic range of the amplifier. Further, the extended dynamic range optical amplifier can use residual pump power from an initial stage to pump the gain mid-stage in the high gain mode. Additionally, the extended dynamic range optical amplifier includes remapping of gain in the initial stage and the gain mid-stage to optimize the amplifier noise performance based on the maximum output power of the amplifier.

An apparatus comprising a processor configured to calculate a noise figure of an optical amplifier for a plurality of selected wavelength channels in a partial-fill scenario that accounts for channel loading. The noise figure is calculated using a plurality of corresponding noise figure correction values at a plurality of wavelengths based on an effective number of channels.

The present invention relates to a method for optimizing performance of a multi-span optical fiber network. Each span has an associated optical transmission fiber connected to an associated optical amplifier. Gain and output power of the associated optical amplifier are respectively controlled independently. An amplifier noise figure respectively depends on the gain of the associated optical amplifier, with each associated optical amplifier further connected to launch optical signals into a remainder of a corresponding optical transmission line. The method includes the steps of for each span, computing the amplifier noise figure and a non-linear noise generated in the span based on information about the span and using the computed amplifier noise figure and the computed non-linear noise to compute an optimum launch power, and optimizing performance of the multi-span optical fiber network based on the computed optimum launch powers of all spans.

Noise sources in an ADC circuit can include kT/C noise of a sampling capacitor, noise coupling on to sampling capacitors from digital circuits, and amplifier noise. Also, charge injection from mismatch in sample switches can cause offsets. These various noise sources can be largely canceled or reduced using described techniques. As a result, the size of the sampling capacitors can be greatly reduced, while still achieving significantly improved noise performance and power efficiency for the overall converter.

A power amplifier for use in wireless communication devices is disclosed that reduces the noise generated at the output of the amplifier in the receive band of the wireless communication device. A resonant circuit is inserted between the base ballast resister and the lumped resister. The resonant frequency of the resonant circuit is adjusted to correspond to the frequency offset between the transmission frequency and the frequency corresponding to the peak noise in the receive band of the communication device.

Methods for design and production of highly sensitive active and passive light detecting devices and systems. Orders of magnitude improvement in optical signal detection is made possible in high noise or low contrast scenes. The current invention creates a small spectral difference between two parts of a split light stream. When recombined, the altered light streams partially correlate, and that generates full amplitude signal oscillation at a frequency that depends on the constituent spectrum. The full amplitude signals and spectrum dependent oscillation make signal discrimination much better than intensity-only methods. The effect of read noise, amplifier noise, dark current noise, and thermal noise due to photo detector shunt resistance, become less important when compared to light detection using prior art methods

The invention relates to a feedback type active noise canceling earphone which is mainly composed of a microphone, a phase-shifting filter, an amplifier and a speaker, wherein the noise received by the microphone and the music are subtracted from the music signal output by the audio amplifier to obtain pure noise , the pure noise is superimposed with the music signal, and the high and low frequencies are filtered out through the phase-shift filter, and then amplified and inverted by the audio amplifier to drive the speaker, thereby canceling the external noise. The invention adopts the principle of feedback active closed-loop denoising to design filtering, phase shifting, amplification and compensation circuits, and improves the physical structure of the earphone, the arrangement of the feedback loop, the selection of components and earphone materials, so that the performance of the earphone is more stable , the noise cancellation effect is better, the average noise attenuation of the earphone is 20db in the range of 100-400HZ, and the maximum noise attenuation is 35db.

Examples described herein include methods, devices, and systems which may compensate input data for non-linear power amplifier noise to generate compensated input data. In compensating the noise, during an uplink transmission time interval (TTI), a switch path is activated to provide amplified input data to a receiver stage including a coefficient calculator. The coefficient calculator may calculate an error representative of the noise based partly on the input signal to be transmitted and a feedback signal to generate coefficient data associated with the power amplifier noise. The feedback signal is provided, after processing through the receiver, to a coefficient calculator. During an uplink TTI, the amplified input data may also be transmitted as the RF wireless transmission via an RF antenna. During a downlink TTI, the switch path may be deactivated and the receiver stage may receive an additional RF wireless transmission to be processed in the receiver stage.