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 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.

Noise reduction for a switching amplifier system having a differential output stage and demodulator filter responsive to complementary PWM signals includes generating in-phase PWM signals and gradually adjusting their duty cycle between a low duty cycle and the full duty cycle of the complementary PWM signals, generating full duty cycle PWM signals and gradually shifting their relative phase between in-phase and out-of-phase; and in response to a turn-on signal, adjusting the in-phase PWM signals from low to full duty cycle and shifting the relative phase from in-phase to out-of-phase, and in response to a turn-off signal shifting the relative phase from out-of-phase to in-phase and adjusting the in-phase PWM signals from full to low duty cycle for maintaining balanced charge on the demodulation filter to reduce audible noise.

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 noisegenerated in capacitor charge-discharge process without increasing or modifying chip pins.

The invention discloses a method and a device for eliminating the noise of a balanced-unbalanced conversion amplifier. In an embodiment of the present invention, the output from the current sensing branch of the LNA and the output from the voltage sensing branch of the LNA are summed and scaled by using the control module of the LNA to generate one or more summed and combined Scaled output. The control module also feeds back the summed and scaled output to at least one of the outputs of the current sensing branch and the voltage sensing branch of the LNA.

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.