A Sigma-Delta Modulator System Design with 2-2 Mash Structure

2014 ◽  
Vol 981 ◽  
pp. 121-124
Author(s):  
Yang Yang ◽  
Guo Dong Sun ◽  
Ming Xin Song ◽  
Zhi Ming Wang
Keyword(s):  
System Design ◽  
Input Signal ◽  
Electronic Equipment ◽  
Signal Frequency ◽  
Behavior Model ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Design Efficiency ◽  
Input Signal Frequency ◽  
Modulator Structure

Σ-Δ modulator structure is increasingly becoming complex, it is very necessary to improve the design efficiency by the level of behavior model in the simulation. The paper discussed several important Σ-Δ modulators with ideal factors, and gives corresponding behavior model. Then, the paper shows a behavior level design with non-ideal factors. Under the condition that sample rate is 256 and input signal frequency is 250 KHz, the SNR can get 105 dB, the effective bit can get 16 bit. It can be used in audio and electronic equipment.

A Sigma-Delta Modulator System Design with 1-1-1 Mash Structure

2013 ◽  
Vol 389 ◽  
pp. 568-572
Author(s):  
Ming Xin Song ◽  
Zhi Ming Wang ◽  
Yang Yang
Keyword(s):  
Simulation Model ◽  
System Design ◽  
Input Signal ◽  
Dynamic Range ◽  
Gain Coefficient ◽  
Process Conditions ◽  
Cmos Process ◽  
Audio Frequency ◽  
Sigma Delta Modulator ◽  
Sigma Delta

This paper designs a three cascaded sigma-delta modulator with using mash structure. Analysis of gain coefficient of each module and simulate the modulator for the behavioral level. In 0.5μm CMOS process conditions, the input signal bandwidth is 20 kHz, oversampling rate is 256, SNR of the simulation model can get 100.5 dB, and accuracy is greater than 16 bit. Compared with other structures of the modulator, it has more stable and more dynamic range, so it can be applied to audio-frequency circuit.

scholarly journals Reducing the Impact of the Frequency Change on the Formation of Orthogonal Components of the Relay Protection Input Signals

2020 ◽  
Vol 63 (1) ◽  
pp. 42-54 ◽  
Author(s):  
E. A. Romaniuk ◽  
V. Yu. Rumiantsev ◽  
Yu. V. Rumiantsev ◽  
A. A. Dziaruhina
Keyword(s):  
Fourier Transform ◽  
Discrete Fourier Transform ◽  
Digital Filter ◽  
Input Signal ◽  
Digital Filters ◽  
Signal Frequency ◽  
Filter Model ◽  
Input Signal Frequency ◽  
Orthogonal Components ◽  
The Impact

Digital filters made with the use of discrete Fourier Transform are applied in most microprocessor protections produced both in the home country and abroad. When the input signal frequency deviates from the value to which these filters are configured, a signal is generated at their output with oscillation amplitude that is proportional to the deviation of the signal frequency from the specified one. The article proposes an algorithm for compensating the oscillations of orthogonal components of the output signals of digital filters implemented on the basis of a discrete Fourier transform, when the input signal frequency deviates from the nominal one. A mathematical model of the proposed digital filter with an algorithm for compensating the oscillations of its orthogonal components, as well as a signal model for reproducing input effects, is implemented in the MatLab-Simulink dynamic modeling environment. The digital filter model is provided with two channels, viz. a current channel and a voltage channel, which makes it possible to simulate their operation in relation to protections that use one or two input values, for example, for current and remote protection. Verification of the functioning of the digital filter model with compensation for fluctuations in its output signal was carried out with the use of two types of test effects, viz. a sinusoidal signal with a frequency of 48–51 Hz (idealized effect), and the effects that are close to the real secondary signals of measuring current transformers and voltage transformers in case of short circuits accompanied by a decrease in frequency. The conducted computational experiments with deviation of frequency from the nominal one, revealed the presence of undamped oscillations at the output of standard digital Fourier filters and their almost complete absence in the proposed digital filters. This makes us possible to recommend digital filters based on a discrete Fourier transform supplemented by an algorithm for compensation of fluctuations in the amplitudes of the output signals for the use in microprocessor protection.

scholarly journals Basic Characteristics of IEC Flickermeter Processing

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Jarosław Majchrzak ◽  
Grzegorz Wiczyński
Keyword(s):  
Input Signal ◽  
Standard Test ◽  
Signal Frequency ◽  
Signal Source ◽  
Short Term ◽  
Voltage Fluctuations ◽  
Input Signal Frequency ◽  
A Value ◽  
Bandwidth Limitation ◽  
Basic Characteristics

Flickermeter is a common name for a system that measures the obnoxiousness of flicker caused by voltage fluctuations. The output of flickermeter is a value of short-term flicker severity indicator, . This paper presents the results of the numerical simulations that reconstruct the processing of flickermeter in frequency domain. With the use of standard test signals, the characteristics of flickermeter were determined for the case of amplitude modulation of input signal, frequency modulation of input signal, and for input signal with interharmonic component. For the needs of simulative research, elements of standard IEC flickermeter signal chain as well as test signal source and tools for acquisition, archiving, and presentation of the obtained results were modeled. The results were presented with a set of charts, and the specific fragments of the charts were pointed out and commented on. Some examples of the influence of input signal’s bandwidth limitation on the flickermeter measurement result were presented for the case of AM and FM modulation. In addition, the diagrams that enable the evaluation of flickermeter’s linearity were also presented.

FREQUENCY-SPATIAL TRANSFORMATION: A PROPOSAL FOR PARSIMONIOUS INTRA-CORTICAL COMMUNICATION

1996 ◽  
Vol 07 (05) ◽  
pp. 591-598
Author(s):  
REGEV LEVI ◽  
EYTAN RUPPIN ◽  
YOSSI MATIAS ◽  
JAMES A. REGGIA
Keyword(s):  
Neural Network ◽  
Input Signal ◽  
Cortical Neurons ◽  
External Input ◽  
Resonant Peak ◽  
Signal Frequency ◽  
Spatial Transformation ◽  
Input Signal Frequency ◽  
Mexican Hat ◽  
Impedance Magnitude

This work examines a neural network model of a cortical module, where neurons are organized on a 2-dimensional sheet and are connected with higher probability to their spatial neighbors. Motivated by recent findings that cortical neurons have a resonant peak in their impedance magnitude function, we present a frequency-spatial transformation scheme that is schematically described as follows: An external input signal, applied to a small input subset of the neurons, spreads along the network. Due to a stochastic component in the dynamics of the neurons, the frequency of the spreading signal decreases as it propagates through the network. Depending on the input signal frequency, different neural assemblies will hence fire at their specific resonance frequency. We show analytically that the resulting frequency-spatial transformation is well-formed; an injective, fixed, mapping is obtained. Extensive numerical simulations demonstrate that a homogeneous, well-formed transformation may also be obtained in neural networks with cortical-like “Mexican-hat” connectivity. We hypothesize that a frequency-spatial transformation may serve as a basis for parsimonious cortical communication.

A High-Order Sigma-Delta Modulator Applied in Micro-Accelerometer

2014 ◽  
Vol 609-610 ◽  
pp. 1266-1270
Author(s):  
Jian Yang ◽  
Liang Liu ◽  
Qiu Ye Lv ◽  
Xiao Wei Liu ◽  
Liang Yin
Keyword(s):  
Noise Level ◽  
Signal To Noise Ratio ◽  
High Order ◽  
Signal Frequency ◽  
Cmos Process ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Ideal Situation ◽  
Micro Accelerometer ◽  
The Ideal

In this paper a high-order sigma-delta modulator applied in micro-accelerometer is designed. The modulator chooses the distributed feedback structure. And the signal bandwidth is 500Hz, the oversampling ratio is 250 and sampling frequency is 250KHz. By the MATLAB Simulink simulation, when the input signal is 1g, and the signal frequency is 250Hz, the simulation result is that the noise level is-160dBV at the signal frequency in the ideal situation. And when considering the non-ideal factors, the simulation result shows that the noise level at the input accelerated signal is 20dBV higher than the ideal. The overall circuit was implemented under 0.5 um CMOS process and simulated in Cadence Spectre. The final simulation results show that the signal to noise ratio (SNR) is 97.1dB.

Influence of Alternating Current Frequency on Output Voltage at Electromagnetic Method of Metal Control

2019 ◽  
Vol 945 ◽  
pp. 879-884
Author(s):  
I.R. Kuzeev ◽  
A.S. Valiev ◽  
V.Yu. Pivovarov
Keyword(s):  
Input Signal ◽  
Life Assessment ◽  
Signal Frequency ◽  
Electric Signal ◽  
Continuous Control ◽  
Input Signal Frequency ◽  
Electromagnetic Processes ◽  
Function Graph ◽  
Sinusoidal Function

The equipment of oil refineries and other hazardous production facilities operate under high pressures and temperatures. Such operation conditions require continuous control and equipment remaining operation life period assessment. The existing methods of diagnostics are based on probabilistic remaining life assessment and use data regarding wall thickness variation during the operation process. The present article presents the method of accumulated damage assessment and its approximation to the limiting state, based on electromagnetic processes studying by means of eddy current control method. The main purpose of studies was determination of optimal value of input signal frequency, which could the most informative for determination of regularity of electric signal parameters change depending on the level of accumulated damages. Steel grade 09Г2С samples were used as the subject of studies. The samples were exposed to static tension under constant rate and during the process of samples deformation we measured the value of electric signal under three frequencies: 100 Hz, 10 kHz, and 1 MHz Based on the obtained results we prepared output signal voltage-relative elongation dependencies, which showed that accumulation of plastic deformations in metal leads to reduction of signal amplitude. Particularly interesting was dependence under 1 MHz frequency, under which electromagnetic processes occur in subsurface and surface layers. This dependence was of some regular nature, which was described by means of the sinusoidal function. Graph of the obtained function qualitatively describes the experimental dependence. On the basis of obtained results we can make a conclusion that optimal input signal frequency is within megahertz range, under which difference between the sinusoidal function graph and the empirical curve is minimum.

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