Noise Analysis Method Research Articles

Phase noise in capacitively coupled micromechanical oscillators

Phase noise in capacitively coupled microresonator-based oscillators is investigated. A detailed analysis of noise mixing mechanisms in the resonator is presented, and the capacitive transduction is shown to be the dominant mechanism for low-frequency 1/f-noise mixing into the carrier sidebands. Thus, the capacitively coupled micromechanical resonators are expected to be more prone to the 1/f-noise aliasing than piezoelectrically coupled resonators. The analytical work is complemented with simulations, and a highly efficient and accurate simulation method for a quantitative noise analysis in closed-loop oscillator applications is presented. Measured phase noise for a microresonator-based oscillator is found to agree with the developed analytical and simulated noise models.

Development of method for assessing traffic noise in certain typical conditions

Assessing traffic noise is difficult in certain typical conditions in New York City due to changed street geometries, challenges of collection of non‐traffic noise components, and levels of existing noise affected by heavy traffic at adjacent streets, among other variables. In general, a proportional model, i.e., a logarithmic equation to compute total passenger car equivalents (PCEs), is employed to assess traffic noise impacts based upon the noise methodology and the noise criteria under the City Environmental Quality Review (CEQR) guidelines. However, in some typical conditions, such as significant changes in roadway or street geometry, roadways that currently carry no or very low traffic volumes, and existing noise levels that are the result of multiple sources, the FHWA Traffic Noise Model (TNM) can be used to better compute project‐generated traffic components. This paper presents a development of noise analysis method dealing with these conditions. Once a proportional model identifies any potential noise impacts for screening purposes, TNM computations can be conducted for more thorough and detailed noise analyses. The results demonstrate that while a proportional model provides a practical and convenient noise analysis for most situations, TNM can provide more accurate noise assessments for the conditions listed above.

Testing of Quasi-Ballistic Field-Effect Transistors with Schottky Gate by 1/f Noise Measurements

We perform measurements of the 1/f voltage fluctuations in the channels of quasi-ballistic field-effect transistors with a V-shaped Schottky gate for the first time. Along with dependences typical of this class of devices, we reveal two new characteristics, namely, a specific current dependence of the noise spectrum due to the leakage current through the buffer layer and an unusual dependence of the spectrum shape on the gate voltage, which turns out to be related to the low-quality (or insufficient) training of samples. The obtained results show a high sensitivity of the noise-analysis method to the occurrence of leakage currents and can be used for nondestructive device-quality testing aimed at revealing unstable samples.

Noise analysis methodology for partially depleted SOI circuits

In partially depleted silicon-on-insulator (PD-SOI) technology, signal switching history and intial state of the circuit nodes can affect the device body voltage and also cause parasitic BJT leakage currents, which can lead to significant increase in noise propagation and noise failures. In this brief we explore the effects of input switching history, initial circuit conditions and the parasitic BJT device on all steps in a traditional noise analysis methodology: noise injection, noise propagation, and noise failure criterion. We present a new noise analysis methodology to account for the floating body and the BJT effects in PD SOI technology. We demonstrate the new technique on an industrial microprocessor design in PD SOI and show that the current noise analysis methods do not account for 56% of noise fails.

다물체계내 유연체의 구조기인 소음해석

This paper presents the method for structure borne noise analysis of a flexible body in multibody system. The proposed method is the superposition method using the flexible multibody dynamic analysis and the finite element one. This method is executed in 3 steps. In the 1st step, time dependent quantities such as dynamic loads, modal coordinates and gross body motion of the flexible body are calculated through a flexible multibody dynamic analysis. And frequency response functions of those time dependent quantities are computed through Fourier transforms. In the 2nd step, acoustic pressure coefficients are obtained through structure-acoustic coupling analyses by the finite element method. In the final step, frequency responses of acoustic pressure at the acoustic nodes are recovered through linear superposition of frequency response functions with acoustic pressure coefficients. The accuracy of the proposed method is verified in the numerical example of a simple car model.

Biases in white noise analysis due to non-Poisson spike generation

White noise analysis methods for characterizing neurons typically ignore the dynamics of neural spike generation, assuming that spikes arise from an inhomogeneous Poisson process. We show that when spikes arise from a leaky integrate-and-fire mechanism, a classical white noise estimate of a neuron's temporal receptive field is significantly biased. We develop a modified estimator for linear characterization of such neurons, and demonstrate its effectiveness in simulation. Finally, we apply it to physiological data and show that spiking dynamics may account for changes observed in the receptive fields measured at different contrasts.

Nonspiking and spiking proprioceptors in the crab: nonlinear analysis of nonspiking TCMRO afferents.

The proprioceptor that signals the position and movement of the first joint of crustacean legs provides an excellent system for investigating information processing and transmission in neurons that function in a graded (nonspiking) manner in the context of a simple motor system. The thoracic-coxal muscle receptor organ (TCMRO) spans the thoracic-coxal joint and transmits graded signals to the CNS via two large nonspiking axons. The response characteristics and nonlinear models of the input-output relationship for the two nonspiking TCMRO afferents (S and T fibers) were determined using white noise analysis (Wiener kernel) methods. The best-fitting linear responses of these neurons was similar, as were their second-order kernels. The gains of the afferents slowly increased with increasing frequency and reached a maximum at approximately 40-60 Hz for the S fiber and 60-80 Hz for the T fiber. Above this corner frequency, the gains of both afferents decreased at approximately 20 dB/decade for the remainder of the 220-Hz stimulus bandwidth. The shape of the first-order kernels, and hence the corresponding (linear) gain functions, of both afferents were similar when driven with different amplitudes of noise, covering a 40-fold amplitude range. Predictions of the S fiber response based on the first two Wiener kernels were accurate, with the second-order model producing a mean square error of 6-8%. Second-order Wiener models for the T fiber were less accurate with a mean square error of approximately 22-26%, but this accuracy improved to 10-16% with the incorporation of the third-order term in the Wiener expansion. The effect of cable properties on the transmission of the sensory potentials to the CNS was evaluated by determining the system characteristics using membrane potentials 5-7 mm distal to the transduction site. The major change after transmission along the axon was a low-pass filtering of the sensory signals and consequent reduction in signal bandwidth.

Nonspiking and spiking proprioceptors in the crab: white noise analysis of spiking CB-chordotonal organ afferents.

The proprioceptors that signal the position and movement of the first two joints of crustacean legs provide an excellent system for comparison of spiking and nonspiking (graded) information transfer and processing in a simple motor system. The position, velocity, and acceleration of the first two joints of the crab leg are monitored by both nonspiking and spiking proprioceptors. The nonspiking thoracic-coxal muscle receptor organ (TCMRO) spans the TC joint, while the coxo-basal (CB) joint is monitored by the spiking CB chordotonal organ (CBCTO) and by nonspiking afferents arising from levator and depressor elastic strands. The response characteristics and nonlinear models of the input-output relationship for CB chordotonal afferents were determined using white noise analysis (Wiener kernel) methods. The first- and second-order Wiener kernels for each of the four response classes of CB chordotonal afferents (position, position-velocity, velocity, and acceleration) were calculated and the gain function for each receptor determined by taking the Fourier transform of the first-order kernel. In all cases, there was a good correspondence between the response of an afferent to deterministic stimulation (trapezoidal movement) and the best-fitting linear transfer function calculated from the first-order kernel. All afferents also had a nonlinear response component and second-order Wiener kernels were calculated for afferents of each response type. Models of afferent responses based on the first- and second-order kernels were able to predict the response of the afferents with an average accuracy of 86%.

Phase noise simulation and estimation methods: a comparative study

A comparison of various simulation and estimation methods available to predict the phase noise in oscillators is presented in this paper. The phase noise of two ring oscillators and one radio frequency CMOS oscillator was determined using the Hajimiri and Lee (1998) phase noise analysis method, and the commercial simulators SpectreRF and EldoRF. Good agreement was obtained between the estimated and simulated phase noise performances. These oscillators were fabricated in a 0.35-/spl mu/m CMOS process. The measured data also shows reasonable agreement with the analysis and simulations.

K-2216 ノイズ解析による自然循環BWRの炉心および領域安定性評価(J14-4 & J12 伝熱現象の応用)(J14 & J11 & J12 原子力利用技術と熱問題)

A Noise analysis method was performed to calculate decay ratios from dominant poles of a transfer function by applying AR method to time series of the core inlet flow rate. Experiments were conducted with the SIRIUS facility, which simulates a representative natural circulation BWR. Channel and regional stability decay ratios at the nominal operating condition were determined to be 0.38 and 0.54, respectively, which indicates sufficient margin for the instabilities. Experiments were extended to investigate the effects of the design parameters on stability.

Noise in Externally Linear Filters

This paper presents a systematic noise analysis method for externally linear filters, suitable for hand calculations. As an illustrative example, a log-domain filter is analyzed. Applying this method to an abstract topology, bounds for signal-to-noise ratio are derived for a class of instantaneous companding filters, when total capacitance or total power are limited.

Noise and sensitivity analysis of periodically switched linear circuits in frequency domain

This paper presents new theories and efficient computational methods for noise and sensitivity analysis of multiphase periodically switched linear (PSL) circuits in frequency domain. Tellegen's theorem for PSL circuits in the phasor domain, frequency reversal theorem, and transfer function theorem, are introduced. The adjoint network of PSL circuits is developed using a frequency-domain approach. An adjoint network-based noise analysis algorithm for PSL circuits is proposed. It is shown that the computational overhead associated with multiple noise sources is eliminated by using the transfer function theorem. It is also shown that the excessive cost of computation due to aliasing effects is significantly reduced when the frequency reversal theorem is employed. In sensitivity analysis, the incremental form of Tellegen's theorem for PSL circuits in the phasor domain is introduced and frequency-domain sensitivity of PSL circuits Is obtained. It is shown that frequency-domain sensitivity of PSL circuits is a series summation of the network variables. Both the baseband and sideband frequency components of the network variables contribute to baseband sensitivity. The method yields sensitivities of one output with respect to all circuit elements in one frequency analysis. Sensitivity networks of PSL circuits are introduced. It is demonstrated that both the adjoint and sensitivity network approaches give the same sensitivity. Numerical results computed using the proposed methods are compared with measurement data and those from other CAD tools.

高速プリント配線板におけるクロストークノイズ解析

In this paper, we propose a crosstalk noise analysis method, which can be analysed in a circuit design step. We prepare a library as necessary attribute in crosstalk noise analysis. The net condition which satisfy a noise permissible value calculate from the library and IC condition. The net condition set on a circuit design, and it forward to PCB CAD. We could be analysed on high speed.

Noise analysis of externally linear systems

Noise analysis in externally linear time-invariant systems is complicated by the facts that noise sources may not be stationary and the relationships between the noise sources and the output are generally nonlinear. In this paper, we present a general noise analysis method which can be used to speed up repetitive noise calculations for a given system, and, most importantly, for theoretical investigations of its noise behavior, possibly leading to low-noise design techniques. A current mode syllabic companding and two log-domain filters are analyzed as illustrative examples.

On the problem of monitoring the neutron parameters of the fast energy amplifier

The conceptual Fast Energy Amplifier, proposed by Rubbia et al. consists of a combination of a U-233/Th-232 fuelled fast-neutron subcritical facility with a proton accelerator. An intense beam of 1 GeV protons is injected into liquid lead at the core centre and drives the reactor by producing spallation neutrons. The burst of spallation neutrons produced by a single proton alters the basic neutron statistics which are well known for thermal neutrons in conventional nuclear reactors. A short assessment of standard neutron noise analysis methods is made with respect to monitoring neutron parameter data.

Nonlinear analysis of noise in static and dynamic translinear circuits

For translinear filters, or log-domain filters, calculation of the maximal signal-to-noise-ratio, an important filter specification, is not trivial, due to the inherent companding behavior and the nonstationary nature of the transistor noise sources. To address this issue, a nonlinear noise analysis method is proposed. Based on large-signal calculations, expressions for the first-order noise and signal-noise intermodulation terms are computed. The procedure is generally applicable both to static and dynamic translinear circuits, as illustrated by a number of generic examples.

Low-frequency low-noise circuits design using an E n-In model

In view of the limitations of a R n-Gn model in the low frequency range and the defects of an E n-In model in common use now, this paper builds a complete E n-In model according to the theory of random harmonic. The parameters for the low-noise design such as the equivalent input noisy voltage E ns, the optimum source impedance Z sopt and the minimum noise figure F min can be calculated accurately by using this E n-In model because it considers the coherence between the noise sources fully. Moreover, this paper points out that it will cause the maximum 30% miscalculation when neglecting the effects of the correlation coefficient γ. Using the series-series circuits as an example, this paper discusses the methods for the E n-In noise analysis of electronic circuits preliminarily and demonstrates its correctness through the comparison between the simulated and measured results of the minimum noise figure F min of a single current series negative feedback circuit.

Differential effects of phorbol ester (PMA) on blocker-sensitive ENaCs of frog skin and A6 epithelia.

Activation of protein kinase C with phorbol 12-myristate 13-acetate (PMA) caused complex transient perturbations of amiloride-sensitive short-circuit Na+ currents (INa) in A6 epithelia and frog skins that were tissue and concentration dependent. A noninvasive channel blocker pulse method of noise analysis (18) was used to investigate how PMA caused time-dependent changes of apical membrane epithelial Na+ channel (ENaC) single-channel currents, channel open probabilities (Po), and channel densities (NT). In A6 epithelia, 5 and 50 nM PMA caused within 7 min concentration-dependent sustained decreases of Po (approximately 55% below control, 50 nM) and rapid compensatory transient increases of NT within 7 min ( approximately 220% above control, 50 nM), resulting in either small transient increases of INa at 5 nM PMA or small biphasic decreases of INa at 50 nM PMA. In contrast to A6 epithelia, 50 and 500 nM PMA in frog skin caused after a delay of at least 10 min transient increases of NT to approximately 60-70% above control at 30-60 min. Unlike A6 epithelia, Po was increased approximately 15% above control within 7 min and remained within +/-10-15% of control for the duration of the 2-h experiments. Despite differences in the time courses of secondary inhibition of transport in A6 epithelia and frog skin, the delayed downregulation of transport was due to time-dependent decreases of NT from their preelevated levels in both tissues. Whereas Po is decreased within minutes in A6 epithelia as measured by noise analysis or by patch clamp (8), the discrepancy in regulation of NT in A6 epithelia as measured by noise analysis and patch clamp is most likely explained by the inability of on-cell patches formed before treatment of tissues with PMA to respond to regulation of their channel densities.

Time-dependent stimulation by aldosterone of blocker-sensitive ENaCs in A6 epithelia.

To study and define the early time-dependent response (< or = 6 h) of blocker-sensitive epithelial Na+ channels (ENaCs) to stimulation of Na+ transport by aldosterone, we used a new modified method of blocker-induced noise analysis to determine the changes of single-channel current (iNa) channel open probability (Po), and channel density (NT) under transient conditions of transport as measured by macroscopic short-circuit currents (Isc). In three groups of experiments in which spontaneous baseline rates of transport averaged 1.06, 5.40, and 15.14 microA/cm2, stimulation of transport occurred due to increase of blocker-sensitive channels. NT varied linearly over a 70-fold range of transport (0.5-35 microA/cm2). Relatively small and slow time-dependent but aldosterone-independent decreases of Po occurred during control (10-20% over 2 h) and aldosterone experimental periods (10-30% over 6 h). When the Po of control and aldosterone-treated tissues was examined over the 70-fold extended range of Na+ transport, Po was observed to vary inversely with Isc, falling from approximately 0.5 to approximately 0.15 at the highest rates of Na+ transport or approximately 25% per 3-fold increase of transport. Because decreases of Po from any source cannot explain stimulation of transport by aldosterone, it is concluded that the early time-dependent stimulation of Na+ transport in A6 epithelia is due exclusively to increase of apical membrane NT.

An efficient approach to noise analysis through multidimensional physics-based models

The paper presents a general approach to numerically simulate the noise behavior of bipolar solid-state electron devices through a physics-based multidimensional device model. The proposed technique accounts for noise sources due to carrier velocity and population fluctuations. The power and correlation spectra of the external current or voltage fluctuations are evaluated through a Green's function, linear perturbation theory equivalent to the classical Impedance Field Method for noise analysis and its generalizations. The numerical implementation of the method is performed through an efficient technique, which allows noise analysis to be carried out with negligible overhead with respect to the small-signal simulation. Some case studies are analyzed in order to compare the present approach with theoretical results from the classical noise theory of p-n junctions and bipolar transistors.