Nil-potent vacuum in homodyne noise

In the absence of a signal field, vacuum entering through the empty beam splitter port is considered to be the sole contributor to the output noise of conventional two-port homodyne detection. We study a modified configuration that alters the input coefficient of vacuum, predicting an output noise less than that of the conventional configuration. Measurements, however, reveal identical output noise profiles for both the configurations. We explain the observations in terms of the incident field noise alone, and suggest that vacuum does not contribute to homodyne noise or shot-noise. We extend our results to the measurement of squeezed light, with non-ideal detectors.

Maximized redundant and synergistic information transfers predict the rise in the output gene expression noise in a generic class of coherent type-1 feed-forward loop networks

We apply the partial information decomposition principle to a generic coherent type-1 feed-forward loop (C1-FFL) motif with tunable direct and indirect transcriptional regulations of the output gene product and quantify the redundant, synergistic, and unique information transfers from the regulators to their target output species. Our results which are obtained within the small-noise regime of a Gaussian framework reveal that the redundant and synergistic information transfers are antagonistically related to the output noise. Most importantly, these two information flavors are maximized prior to the minimization and subsequent growth of the output noise. Therefore, we hypothesize that the dynamic information redundancy and synergy maxima may possibly be utilized as efficient statistical predictors to forecast the increasing trend of the fluctuations associated with the output gene expression dynamics in the C1-FFL class of network motifs. Our core analytical finding is supported by exact stochastic simulation data and furthermore validated for a diversified repertoire of biologically plausible parameters. Since, the output gene product serves essential physiological purposes in the cell, a predictive estimate of its noise level is supposed to be of considerable biophysical utility.

A Simulation Study of Noise Behavior in Basic Current Mirror using CNTFET and MOSFET

We present a aimulation study of noise behavior in basic current mirror using CNTFET and MOSFET, obtaining that the output noise current is always higher for the CNTFET than for the MOS device. Keywords— CNTFET, MOSFET, Modelling, Current Mirror Design, Advanced Design System (ADS).

High-Order Filtered PID Controller Tuning Based on Magnitude Optimum

The paper presents a tuning method for PID controllers with higher-order derivatives and higher-order controller filters (HO-PID), where the controller and filter orders can be arbitrarily chosen by the user. The controller and filter parameters are tuned according to the magnitude optimum criteria and the specified noise gain of the controller. The advantages of the proposed approach are twofold. First, all parameters can be obtained from the process transfer function or from the measured input and output time responses of the process as the steady-state changes. Second, the a priori defined controller noise gain limits the amount of HO-PID output noise. Therefore, the method can be successfully applied in practice. The work shows that the HO-PID controllers can significantly improve the control performance of various process models compared to the standard PID controllers. Of course, the increased efficiency is limited by the selected noise gain. The proposed tuning method is illustrated on several process models and compared with two other tuning methods for higher-order controllers.

Low Distortion of Noise Filter Realization with 6.34 V/μs Fast Slew Rate and 120 mVp-p Output Noise Signal

In order to reduce Gaussian noise, this paper proposes a method via taking the average of the upper and lower envelopes generated by capturing the high and low peaks of the input signal. The designed fast response filter has no cut-off frequency, so the high order harmonics of the actual signal remain unchanged. Therefore, it can immediately respond to the changes of input signal and retain the integrity of the actual signal. In addition, it has only a small phase delay. The slew rate, phase delay and frequency response can be confirmed from the simulation results of Multisim 13.0. The filter outlined in this article can retain the high order harmonics of the original signal, achieving a slew rate of 6.34 V/μs and an almost zero phase difference. When using our filter to physically test the input signal with a noise level of 3 Vp-p Gaussian noise, a reduced noise signal of 120 mVp-p is obtained. The noise can be suppressed by up to 4% of the raw signal.

Butterworth filters as tracking differentiators

<div> <div> <div> <p>This letter describes how traditional Butterworth low pass filters can enhance the performance of the tracking differentiator introduced by Han by mitigating the effect of additive high frequency noise that corrupts the output measurement. The tracking differentiator obtains much of its utility from its realization in cascaded integral form. By combining the cascaded integral form realization of Butterworth low pass filters with its the noise rejection features one can design a tracking differentiator that is efficiently tuned to reject high frequency output noise. </p> </div> </div> </div>

Butterworth filters as tracking differentiators

<div> <div> <div> <p>This letter describes how traditional Butterworth low pass filters can enhance the performance of the tracking differentiator introduced by Han by mitigating the effect of additive high frequency noise that corrupts the output measurement. The tracking differentiator obtains much of its utility from its realization in cascaded integral form. By combining the cascaded integral form realization of Butterworth low pass filters with its the noise rejection features one can design a tracking differentiator that is efficiently tuned to reject high frequency output noise. </p> </div> </div> </div>