Sine wave

About: Sine wave is a research topic. Over the lifetime, 12183 publications have been published within this topic receiving 93013 citations. The topic is also known as: sinusoid.

High efficiency MOSFET sine wave generator

Abstract: A high efficiency MOSFET sine wave generator is provided using the class D pulse width modulation principle. A triangle wave at f₀ is compared to a variable amplitude sinusoid at about 1/10 f₀ to provide a pulse width modulated signal for driving a pair of power MOSFETS connected for switching a B+ and a B- power supply. The power switch output is LC filtered and fedback for regulating the amplitude of the modulating sinusoid.

Three-dimensional shape measurement method and device and record medium

Abstract: PROBLEM TO BE SOLVED: To achieve practical three-dimensional shape measurement by combining at least one light source and a camera. SOLUTION: A control means 253 repeats a processing for picking up an image with cameras 203 and 204 by shifting the phase value of a sinusoidal wave light pattern from light projectors 201 and 202 by 2 π/4 at a time for four times, a phase calculation means 210 inputs an image signal and outputs a phase signal 13 for each pixel from an image group that is shot by the sinusoidal wave light pattern with a different phase, absolute phase determination means 215-220 input two of phase signals 15-18, determine the absolute phase value of a pixel position for determining the absolute phase, and outputs the absolute phase signal, and an absolute phase conversion means 221 inputs a phase signal and an absolute phase signal that are switched by a three-dimensional coordinates calculation control signal 33, refers to the absolute phase signal, and converts the phase value at the pixel position where the absolute phase in the phase signal has not been determined is converted to an absolute phase, a three-dimensional coordinates conversion means 222 inputs an absolute phase conversion signal 32 and a three-dimensional coordinates calculation control signal 33 and outputs a three-dimensional coordinates signal 34, and a three-dimensional coordinates synthesis means 226 inputs three-dimensional coordinates signals 35-38, synthesizes four shape information, and outputs a synthesis three-dimensional coordinates signal 39.

An analog memory integrated circuit for waveform sampling up to 900 MHz

Abstract: The design and implementation of a switched-capacitor memory suitable for capturing high-speed analog waveforms is described. Highlights of the presented circuit are a 900 MHz sampling frequency (generated on chip), input signal independent cell pedestals and sampling instances, and cell gains that are insensitive to component sizes. A two-channel version of the memory with 32 cells for each channel has been integrated in a 2-/spl mu/m complementary metal oxide semiconductor (CMOS) process with polysilicon-to-polysilicon capacitors. The measured rms cell response variation in a channel after cell pedestal subtraction is less than 0.3 mV across the full input signal range. The cell-to-cell gain matching is better than 0.01% rms, and the nonlinearity is less than 0.03% for a 2.5-V input range. The dynamic range of the memory exceeds 13 bits, and the peak signal-to-(noise+distortion) ratio for a 21.4 MHz sine wave sampled at 900 MHz is 59 dB. >

Computer‐controlled apparatus for measuring complex elastic, dielectric, and piezoelectric constants of polymer films

Abstract: Principles and design details are described for a fully automatic system measuring frequency and temperature spectra of the complex elastic, dielectric, and piezoelectric constants of polymer films. A microcomputer is used to control all processes including wave generation, sampling, and calculations. A sinusoidal excitation wave is written onto a RAM, readout by an external clock, and applied to a sample via a D/A converter. The resulting signals related to force, deformation, charge, and voltage are simultaneously sampled using the same clock and are determined as complex quantities through Fourier transformation. Their ratios give corresponding complex response functions. A multifrequency signal consisting of eight sinusoidal waves with frequencies of common ratio 2 is used to obtain frequency spectra over two decades at a time. This system operates over a frequency range from 0.01 to 100 Hz for elastic and piezoelectric measurements and from 0.01 Hz to 10 kHz for dielectric measurements at temperature...

Modulation Method Including Noise Model for Minimizing the Wiggling Error of TOF Cameras

Abstract: Registered depth and intensity data at a high frame rate, a compact design, low weight, and a reduced power consumption have motivated the increasing usage of lock-in time-of-flight (TOF) cameras in research areas such as computer graphics, machine vision, and robotics. The state-of-the-art practice is to use continuous wave modulation with square waves for TOF cameras. Square waves can be easily generated digitally with a high accuracy and stability using programmable logic devices. In this paper, a modulation method based on sine waves is proposed, which significantly reduces the depth distortion offset (wiggling effect) of lock-in TOF cameras. Furthermore, a model for the noise distribution in the depth image is derived. This model can predict the performance of the proposed modulation method for each pixel in real time.