Noise In Measured Data Research Articles

An analytical channel thermal noise model for deep-submicron MOSFETs with short channel effects

In this work, an analytical channel thermal noise model for short channel MOSFETs is derived. The transfer function of the noise was derived by following the Tsividis’ method. The proposed model takes into account the channel length modulation, velocity saturation, and carrier heating effects in the gradual channel region. Modeling results show good agreements with the measured noise data.

New disc type switched reluctance motor for high torque density

A new disc type switched reluctance motor (DSRM) structure for high torque density is presented. The new motor has a double sided stator structure that provides higher torque and less acoustic noise than classical switched reluctance motors (SRMs) of small sizes. The motor is based on linear switched reluctance motors. The results of the analytical and numerical analysis are given to evaluate the effectiveness of the motor structure, and experimental noise measurement data are presented. In the numerical analysis, due to the highly nonlinear nature of the motor, finite element analysis is employed. A prototype 6/4 DSRM and a classical SRM are built and tested for experimental studies. The obtained test and simulation results show that the DSRM has a higher torque and less acoustic noise performance.

Li-ion battery SOC estimation method based on the reduced order extended Kalman filtering

The extended Kalman filter (EKF) method for SOC estimation has some problems such as the lack of an accurate model, and model errors due to the variation in the parameters of the model due to the nonlinear behavior of a battery. To solve the aforementioned issues, this paper proposes a reduced order EKF including the measurement noise model and data rejection. In order to do so, the model of a battery in the EKF is simplified into the type of reduced order to decrease the calculation time. Additionally, to compensate the model errors caused by the reduced order model and variation in parameters, a measurement noise model and data rejection are implemented because the model accuracy is critical in the EKF algorithm in order to obtain a good estimation. Finally, the proposed algorithm is verified by short and long term experiments.

Shot Noise Modeling in Metal-Oxide-Semiconductor Field Effect Transistors under Sub-Threshold Condition

We have developed a new simulation methodology for predicting shot noise intensity in Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET). In our approach, shot noise in MOSFETs is calculated by employing a two dimensional device simulator in conjunction with the shot noise model of a p-n junction. The accuracy of the noise model has been demonstrated by comparing simulation results with measured noise data of p-n diodes. The intensity of shot noise in various n-MOSFET devices under various bias conditions was estimated beyond GHz operational frequency by using our simulation scheme. At DC or low-frequency region, sub-threshold current dominates the intensity of shot noise. Therefore, shot noise is independent on frequency in this region, and its intensity is exponentially depends on V G , proportional to L -1 , and almost independent on V D . At high-frequency region above GHz frequency, on the other hand, shot noise intensity depends on frequency and is much larger than that of low-frequency region. In particular, the intensity of the RF shot noise is almost independent on L, V D and V G . This suggests that high-frequency shot noise intensity of MOSFETs is decided only by the conditions of source-bulk junction.

750 kW 풍력발전기의 소음 실증

This study introduces an environmental noise evaluation procedure for wind turbines(W/T) and the evaluation result of a 750 kW wind turbine(W/T) system. Test and evaluation are performed according to the international standard IEC 61400-11 on J48 W/T which is under operation in Daekwanryung W/T test site. With the meteorological data and W/T operational data, noise data are monitored and analysed. An integrated monitoring system is constructed in the test site and is utilized for the evaluation. From the measured noise data, acoustic power level, directivity and tonality of the W/T are estimated under the wind speeds required fly the International standard. The purpose of the study is to establish an W/T noise evaluating system satisfying the international standard and to obtain noise data for home made 750 kW W/T.

군용항공기 소음평가 단위에 관한 연구

Korean `Law of Aviation` and `Test Method of Measuring Noise and Vibration` designate to use WECPNL metric based on measurement for the accessment of aircraft noise in Korea. However, time duration of noise event can not be considered in metric in principle, compensation on the duration has been utilized. A study was done recently to evaluate appropriate duration compensation for the accessment of military aircraft noise under current metric of WECPNL and . This study was carried out to evaluate what metric is the most appropriate to express aircraft noise including time duration of single noise event, computing and comparing noise exposure with 1 second noise measurement data of military aircraft in , and SEL. This study shows SEL is the most appropriate noise metric for the evaluation of noise exposure with time duration such as aircraft noise without compensation. It is suggested to use SEL noise metric instead of noise metric with duration compensation for the aircraft noise accessment either military aircraft or civilian aircraft.

The effects of extended depletion region on noise modeling of HEMT's

In this work we have extended the analytical model on noise, by taking into account the effect of the depletion region that extends into the gate to drain spacing. The model utilizes the charge-control model based on analytical functions that relate 2-D electron gas concentration and the Fermi level. The effects of this high field extension region on the noise performance of the device have been investigated. Using the proposed model, the noise characteristics of two HEMTs are analytically calculated and compared with the measured data. It is observed that the contribution of the extended depletion region to the overall device noise is rather significant and it should not be ignored. The theoretical predictions based on the model are found to be in good agreement with the measured noise data.

Development of ship radiated noise transfer functions and near-field to far-field measured signature comparisons

Various methods exist to determine the vibration level on the wetted hull plate of a vessel—whether they be measured or predicted. Transfer functions are discussed that relate the hull vibration levels and ship’s physical parameters to the far-field radiated noise. These methods are useful to predict the noise from fisheries research vessels and other vessels such as work or cruise boats. The former need to ‘‘sneak-up’’ on fish to perform stock assessment and the latter may need to operate in environmentally sensitive areas. Predicted radiated noise is compared to measured noise to assess the accuracy. Data is also presented on measured noise data for several vessels at various separation distances approximating near- and far-field conditions. These data were taken with the vessel at zero speed.

Application of Discrete Wavelet Transform in a Combustion Chamber to Turbulence Measurement with LDV (Removing Noise in Measurement Data Using Wavelet Shrinkage)

In this study, the influence of the measurement noise in LDV measurements were considered, and how to remove the noise using Complex Discrete Wavelet Transform (CDWT) was proposed. Then turbulent velocity in the combustion chamber measured with an LDV was analyzed. The major results can be summarized as follows : 1) The influence of the noise in the turbulent velocity becomes large as frequency increases. Therefore, a setup of cutoft frequency is difficult when removing the noise with a lowpass filter. 2) In this case, it is effective to remove the noise using the CDWT because of improvement of translation invariance.

Compact modelling of noise for RF CMOS circuit design

The thermal noise of short-channel NMOS transistors in a commercially available 0.13 -μm CMOS technology is studied. The experimental results are modelled with a non-quasi-static RF model, based on the principle of channel segmentation. The model is capable of predicting both drain and gate current noise accurately, without fitting any parameters to the measured noise data. An essential ingredient of the model is the gate resistance, which is shown to dominate the gate current noise. In the optimised device layouts, this gate resistance is mainly determined by the silicide-to-polysilicon contact resistance.

Influence of expanding ring roads on traffic noise in Beijing City

The road network in Beijing is expanding in the form of loop-lines. Following the 2nd and 3rd ring roads, the 4th has been completed and come into operation in 2002. Traffic noise surveying and analysis was performed along four main roads in the Beijing urban area—the 2nd, 3rd and 4th ring roads circling the central downtown area and Chang-An Avenue, a major east–west corridor through the heart of the city. Measured noise data along the 2nd, 3rd and Chang-An Avenue were compared with the data surveyed before the completion of the 4th ring road for determining influence of expanding ring roads on traffic noise pattern in Beijing City. The results indicate that these main roads remain overloaded by traffic flow during daytime, and noise levels due to road traffic along these roads exceeds relavent environmental standards by 5 dBA. Reduced traffic noise level was observed along the northern half of the 2nd and 3rd ring roads, and along the central section of Chang-An Avenue. Increased traffic noise level was observed along the southern half of the 2nd and 3rd ring roads, and along the non-central section of Chang-An Avenue. Expanding ring roads mitigate heavy traffic flow in the central part of Beijing City, but spread high traffic noise outwards at the same time.

Defect spectroscopy using 1/ fγ noise of gate leakage current in ultrathin oxide MOSFETs

The electrical trap properties in ultrathin oxide MOSFETs are extracted using 1/ f γ low frequency noise components of gate leakage current. The technique is based on the low frequency noise measurements which are capable of probing trap states over the energy and space. The gate voltage is swept between 0.4 and 1.32 V to obtain the different power slopes γ of 1/ f γ noise spectrum. From the measured noise data, the trap parameters such as slow trap densities and capture cross-section are accurately determined as a function of trap energy and trap distance. The 1/ f γ noise measurement results confirm that the capture cross-sections depend strongly on the surface potential, and the slow trap densities estimated near the band edge and at the Si–SiO 2 interface are higher than those near the midgap and deeper distance. Moreover, the parallel conductance spectroscopy of slow traps is reproduced by 1/ f γ low frequency noise measurements, and is verified by the low frequency plateau in measured conductance loss G p( f)/ w. For the purpose of investigating the dependency of trap parameters on the complex admittance of oxide traps, the Cole–Cole plots for different trap profiles, a uniform and exponentially decreasing trap distribution in space, are calculated using the theoretical model. The noise spectroscopy technique further reveal the dynamic evolution of trap states and gives a clear physical understanding of the pertinent low frequency noise sources.

Simulation of oxide trapping noise in submicron n-channel MOSFETs

Carrier trapping via tunneling into the gate oxide was implemented into a partial differential equation-based semiconductor device simulator to analyze the 1/f-like noise in silicon MOSFETs. Local noise sources are calculated using the carrier tunneling rates between trap centers in the oxide and those at the interface. Using the Green's transfer function approach, noise contributions from each node in the oxide mesh to the overall noise at the specified contact terminals are simulated. Unlike traditional 1/f noise analyses in MOSFETs, the simulator is capable of simulating noise for a wide range of bias voltages and device structures. The simulation results show that for an uniformly doped channel, the region in the oxide above the pinch-off point in saturation is most critical for low frequency noise generation while for a graded channel device the source side of the gate oxide region becomes important. By comparing the simulation results with the measured noise data, the oxide defect density in the noise producing regions can be profiled.

Simulations of generation–recombination noise of n– i– n a-Si:H devices using AMPS-1D

AMPS-1D is an accepted computer program to simulate time-averaged electrical properties of a-Si:H devices. In this paper, AMPS-1D is applied to calculate resistance fluctuations produced by generation–recombination ( g– r) processes at defects in 1.56-μm thick n– i– n devices. The results are compared to measured noise data. Calculated differential g– r rates appear to coincide with the observed characteristic noise frequencies for all temperatures, when taken at 0.35 μm from the contact and correspond to the calculated inverse electron lifetimes. The position-dependent g– r rate explains why a distribution of rates is observed in the noise spectra in a-Si:H.

連続消音エルボの気流による発生騒音について

In this paper, for evaluating the aerodynamic noise of double lined elbows, the sound power levels for 34 kinds of them are measured. They are formed from three combinations for two single lined elbows, two kinds of connection directions and seven kinds of duct length between the two elbows. The aerodynamic noise are shown in relation with the mean velocity in inlet ducts and the over all power levels. The measurement data of the aerodynamic noise for double lined elbows are compared with the value synthesized data of the aerodynamic noise for two single lined elbows. Then the frequency characteristics of the aerodynamic noise are examined in the relative band power level based on the over all power level.

Performance of honeywell RICMOS-IV SOI transistors after irradiation to 27 Mrad(si) by 63.3 MeV protons

We present results of an exposure of Honeywell RICMOS-IV SOI transistors produced in a developmental run to 2 × 10 14 63.3 MeV protons at the UCD cyclotron radiation test beam (27 Mrad (Si)). In terms of surface damage, this corresponds to almost twice the dose expected for the CMS pixel detector during its useful life at the LHC collider. The irradiated transistors include n-channel MOSFETs similar to the front-end transistors of a pixel readout suitable for use at hadron colliders. Data are presented for MOSFETs on radiation-induced changes in thresholds, transconductance, maximum voltage gain and noise. Circuit simulations using the measured noise data indicate that the pixel readout would continue to function satisfactorily in the CMS radiation environment.

Voltage transients in electromigration noise measurement data

Abstract The 1/f2 noise measurement technique used for determination of electromigration lifetime has had only limited practical success. The correlation of noise magnitude to lifetime is high but the results are inconsistent. In this paper the source of the inconsistent results is identified and demonstrated. The presence of voltage transients in noise data, caused by abrupt changes of resistance in a thin-film test structure, is shown to be the primary source of 1/f2 noise in the 1–10 Hz frequency range. The transients do not appear consistently in the data and are strongly affected by typical data handling techniques such as windowing. The combination of these factors explains the inconsistent results obtained when using the 1/f2 noise measurement technique.

Urban noise survey for the city of Porto Alegre, Brazil

This paper presents the methods and results of a simplified traffic noise survey for the city of Porto Alegre, the southmost capital city in Brazil. Noise measurement data and hourly vehicle flow data were used. Both were obtained at 6 p.m. Values from 560 sites were considered, making possible the construction of a simplified traffic noise map, built upon Leq values. The work, which tries to identify, for the stated time, the impact of noise on the population, in terms of the magnitude of the population exposed to different noise levels, has shown that 90% of the population included in the sample is exposed to A-weighted noise levels exceeding 65 dB.

Assessment of low-frequency noise in dwellings. New Polish recommendations

The paper presents the new Polish recommendations for evaluation of low-frequency noise penetrating into dwellings from appliances installed inside or outside of building. Based on measurement data of annoyance noise, epidemiological investigations of the influence of noise on the health of exposed inhabitants, laboratory tests of thresholds of narrow- and broadband noise perception, review of the present literature, the new assessment criteria was proposed. In order to assess the noise spectra measured in dwellings, the A10 characteristics as the rating curve have been accepted. Its L levels for one-third-octave bands are determined by relation: LA10=10 kA. The low-frequency noise occurs as annoying when the sound pressure levels of noise exceeds the levels of A10 curve and exceeds the background noise by more than: 10 dB for tone noise and 6 dB for broadband noise.

Performance of noise indices in office environment dominated by noise from human speech

An acoustical environment survey was carried out in six similar air conditioned landscaped offices in which human speech was considered to be the major source of complaint. Both questionnaire and physical noise measurement were administrated. Physical noise measurement data reveal higher sound energy within the human speech frequency range and high speech intelligibility level in the offices. Results also show that the preferred noise criterion gives good correlation with the auditory sensation comments of the office workers. The noise climate, the equivalent sound pressure level and the noise pollution level are also found to be useful in assessing the acoustical environment inside the surveyed offices.