Analysis Of Noise Performance Research Articles

Impact of Interface Trap Charges on Silicon Carbide (4H-SiC) Based Gate – Stack, Dual Metal, Surrounding Gate, FET (4H-SiC- GSDM-SGFET) for Analog and Noise Performance Analysis for 5 G/LTE Applications

This article examines the impact of various interface trap charges on silicon carbide-based gate—stack, dual metal, surrounding gate, FET (4H-SiC-GSDM-SGFET). It has been contrasted for performance with silicon carbide (4H-SiC)-based dual metal, surrounding gate, FET (4H-SiC-DM- SGFET). For both devices, output characteristics including transconductance (gm), output conductance (gd), drain current (Ids), gate capacitance (Cgg), cutoff frequency (fT) and threshold voltage (Vth) have been examined. Surface potential and electron concentration were also inspected using a contour plot for both the device structures. A gate-stack with a high k- dielectric, Lanthanum oxide (La2O3) along with gate dielectric layer Aluminum oxide (Al2O3) was used for proposed structure implementation. Additionally, we investigated how trap charges affect noise figure (NF) and noise conductance (NC). Also, a CMOS inverter has been developed and its output characteristics have been compared for both the device architectures. ATLAS 3-D device simulator has been employed to conduct the simulations.

Edge-Terminated AlGaN/GaN/AlGaN Multi-Quantum Well Impact Avalanche Transit Time Sources for Terahertz Wave Generation

Edge-Terminated AlGaN/GaN/AlGaN Multi-Quantum Well Impact Avalanche Transit Time Sources for Terahertz Wave Generation

Fast kV-switching and dual-layer flat-panel detector enabled cone-beam CT joint spectral imaging

Purpose. Fast kV-switching (FKS) and dual-layer flat-panel detector (DL-FPD) technologies have been actively studied as promising dual-energy spectral imaging solutions for FPD-based cone-beam computed tomography (CT). However, cone-beam CT (CBCT) spectral imaging is known to face challenges in obtaining accurate and robust material discrimination performance. That is because the energy separation by either FKS or DL-FPD, alone, is still limited, along with apparently unpaired signal levels in the effective low- and high-energy projections in real applications, not to mention the x-ray scatter in cone-beam scan which will make the material decomposition almost impossible if no correction is applied. To further improve CBCT spectral imaging capability, this work aims to promote a source-detector joint multi-energy spectral imaging solution which takes advantages of both FKS and DL-FPD, and to conduct a feasibility study on the first tabletop CBCT system with the joint spectral imaging capability developed. Methods. For CBCT, development of multi-energy spectral imaging can be jointly realized by using an x-ray source with a generator whose kilo-voltages can alternate in tens of Hertz (i.e. FKS), and a DL-FPD whose top- and bottom-layer projections corresponds to different effective energy levels. Thanks to the complimentary characteristics inherent in FKS and DL-FPD, the overall energy separation will be significantly better when compared with FKS or DL-FPD alone, and the x-ray photon detection efficiency will be also improved when compared with FKS alone. In this work, a noise performance analysis using the Cramér–Rao lower bound (CRLB) method is conducted. The CRLB for basis material after a projection-domain material decomposition is derived, followed by a set of numerical calculations of CRLBs, for the FKS, the DL-FPD and the joint solution, respectively. To compensate for the slightly angular mismatch between low- and high- projections in FKS, a dual-domain projection completion scheme is implemented. Afterwards material decomposition from the complete projection data is carried out by using the maximum-likelihood method, followed by reconstruction of basis material and virtual monochromatic images (VMI). In this work, the first FKS and DL-FPD jointly enabled multi-energy tabletop CBCT system, to the best of our knowledge, has been developed in our laboratory. To evaluate its spectral imaging performance, a set of physics experiments are conducted, where the multi-energy and head phantoms are scanned using the 80/105/130 kVp switching pairs and projection data are collected using a prototype DL-FPD, whose both top and bottom layer of panels are composed of 550 μm of cesium iodine (CsI) scintillators with no intermediate metal filter in-between. Results. The numerical simulations show that the joint spectral imaging solution can lead to a significant improvement in energy separation and lower noise levels in most of material decomposition cases. The physics experiments confirmed the feasibility and superiority of the joint spectral imaging, whose CNRs in the selected regions of interest of the multi-energy phantom were boosted by an average improvement of 21.9%, 20.4% for water basis images and 32.8%, 62.8% for iodine images when compared with that of the FKS and DL-FPD, respectively. For the head phantom case, the joint spectral imaging can effectively reduce the streaking artifacts as well, and the standard deviation in the selected regions of interest are reduced by an average decrement of 19.5% and 8.1% for VMI when compared with that of the FKS and DL-FPD, respectively. Conclusions. A feasibility study of the joint spectral imaging solution for CBCT by utilizing both the FKS and DL-FPD was conducted, with the first tabletop CBCT system having such a capability being developed, which exhibits improved CNR and is more effective in avoiding streaking artifacts as expected.

Noise performance analysis of PT-symmetric non-reciprocal transmission systems

Non-reciprocity is a crucial concept in the field of signal transmission and processing as it protects sensitive elements from the effects of feedback signal. The non-reciprocal components based on ferrite materials are bound to show shortcomings due to incompatibility with chip-level ICs. In recent years, parity-time (PT)-symmetric non-reciprocal transmission in electronic systems has been proposed and analyzed. Here, we propose the simplified noise analysis model based on a PT-symmetric non-reciprocal transmission system. And we verify the theoretical noise model by simulation analysis and experimental demonstrations. The experimental result shows that the noise figure of the proposed PT-symmetric non-reciprocal transmission device is 7.5 dB because of the employment of the active amplifier. This work establishes a noise performance analysis framework, providing guidance for the development of lossless and miniaturized applications of non-reciprocal components.

Noise Performance Analysis and Optimization of Downsampling Heterodyne Φ-OTDR

Noise Performance Analysis and Optimization of Downsampling Heterodyne Φ-OTDR

Design and Implementation of C-Band Frequency Synthesizer Using LMX2592 IC

The paper presents the design scheme and implementation of a PLL-based-frequency synthesizer using LMX2592 IC. The frequency synthesizer have vital role in the development of up-converter and down-converter equipments. Therefore, on the RT-Duroid RO4350 substrate, a low phase noise and stable carrier generator is designed and implemented. Graphical User Interface (GUI) & LAN based programming is developed to easily change the synthesizer frequency. The control system analysis using root locus and bode plot is presented for system stability.The experimental results representing the performance parameters, like frequency range, frequency step size, output power, phase noise, carrier stability, harmonics, and spurious, etc., are also presented in the paper. The analysis of spurious and phase noise performance at near integer boundary conditions are done by changing loop bandwidth and phase margin.

Single-longitudinal-mode short-cavity Brillouin random fiber laser via frequency auto-tracking with unpumped-EDF sagnac loop

A single-longitudinal-mode high-coherence Brillouin random fiber laser (BRFL) with low-noise and narrow linewidth is proposed and experimentally demonstrated, which owns the shortest cavity structure ever reported in BRFL configuration by the combined utilization of highly nonlinear fiber (HNLF) and unpumped Er-doped-fiber sagnac loop (UESL). In this BRFL, stimulated Brillouin scattering and Rayleigh scattering are exploited to provide the resonant gain and random distributed feedback, respectively. The UESL, with a narrow bandpass width and a capability of auto-tracking the center frequency of the transmitted light, is realized by forming a dynamic fiber grating (DFG) filter with periodically modulated refractive index through the saturable absorption effect and hole-burning effect along the Er-doped fiber. The UESL can effectively act as a center-frequency-auto-tracking bandpass filter with narrow bandwidth to filter out the undesired dense random modes and simultaneously restrict the resonant modes within a very limited frequency range. It thus suppresses the modes hopping and multi-mode resonances within the Brillouin gain bandwidth so that the frequency jitter and instability of laser output are greatly alleviated. The short cavity was realized by utilizing a section of HNLF with high nonlinearity coefficient (≥10 W−1·km−1 @1550 nm), which can provide enough Brillouin gain for the BRFL when short length is employed. Compared with the currently prevalent BRFLs based on long-cavity configurations, the short-cavity structure enables a significant reduction in the number of random cavity modes so as to guarantee a high probability for the single-longitudinal-mode random lasing output. In the experiment, a stable single-longitudinal-mode lasing output with an ultra-narrow linewidth of ∼802.42 Hz is obtained from the proposed BRFL. Statistical characteristics of the mode resonances, laser noise performance and statistical analysis of the lasing output are also experimentally investigated for the proposed BRFL. In addition, broadband wavelength-tunable output is realized in the proposed BRFL.

High SNR rapid T1 -weighted MPRAGE using spiral imaging with long readouts and improved deblurring.

The goal of this work is to present the implementation of 3D spiral high-resolution MPRAGE and to demonstrate that SNR and scan efficiency increase with the increment of readout time. Simplified signal equations for MPRAGE indicate that the T1 contrast can be kept approximately the same by a simple relationship between the flip angle and the TR. Furthermore, if T1 contrast remains the same, image SNR depends on the square root of the product of the total scan time and the readout time. MPRAGE spiral sequences were implemented with distributed spirals and spiral staircase on 3 Tesla scanners. Brain images of threevolunteers were acquired with different readout times. Spiral images were processed with a joint water-fat separation and deblurring algorithm and compared to Cartesian images. Pure noise data sets were also acquired for SNR evaluation. Consistent T1 weighting can be achieved with various spiral readout lengths, and between spiral MPRAGE imaging and the traditional Cartesian MPRAGE imaging. Noise performance analysis demonstrates higher SNR efficiency of spiral MPRAGE imaging with matched T1 contrast compared to the Cartesian reference imaging. Fast, high SNR MPRAGE imaging is feasible with long readout spiral trajectories.

Analysis of Noise in Current Mirror Circuits Based on CNTFET and MOSFET

In this paper we present a comparative analysis of noise performance of Carbon Nanotube Field Effect Transistors (CNTFETs) and MOSFET, through the design of two circuits: a basic current mirror and self-bias current mirror, each time with different current values. For this aim we use a semi-empirical compact CNTFET model, already proposed by us, including noise source contributions, and the BSIM4 model for MOS device. Then we analyze and discuss the spectral density of output noise current, comparing the two considered technology. The software used is Advanced Design System (ADS), compatible with the Verilog A programming language.

Tip vortex cavitation of propeller bionic noise reduction surface based on precision abrasive belt grinding

The processed surface integrity of the propeller has a vital impact on the performance, efficiency, and noise of the entire power energy conversion device, and the bionic micro-structured surface is conducive to improving the noise reduction performance of the working parts. In this paper, the microstructure of the propeller blade surface is machined by precision abrasive belt grinding. Based on the surface roughness detection and 3D morphology analysis results, a univariate model of propeller surface groove with V-shaped section is established. The flow field analysis, numerical analysis of cavitation, and noise performance analysis of general marine propellers and bionic marine propellers are also carried out. The results show that the maximum noise of the propeller with the bionic grooved surface is 94.7 decibels, and the maximum noise of the general propeller is 146 decibels. The noise reduction effect is increased by 35%, which provides a new method of precision abrasive belt grinding for the noise reduction of the propeller.

Wind noise performance analysis of a prototype compact infrasound array

Previously, presentations have been given at ASA meetings that demonstrated the potential for compact arrays of infrasound sensors achieving high gain against wind noise under appropriate environmental conditions without the use of large windscreens. These presentations focused on using specific models for the spatiotemporal correlation function of the wind noise as part of the processing methodology, and they did not directly address the features of the compact array design that influence performance. This presentation will study the effects of several compact array features on performance using a recently published cross-spectral density model for wall-bounded turbulent pressure fluctuations. Additionally, data from several experiments will be presented including data from a prototype compact infrasound array.

Performance Analysis and Comparison of narrowband noise passing through filter types (Elliptic) and (Butterworth)

This paper introduces the properties of an elliptical filter and Butterworth filter characteristics when narrowband noise passes through them, which has the same behavior in both, traffic and stop range. The amount of ripple in each band can be adjusted independently as it has a faster gain transition between the pass and stop band, so a compression has been made between elliptical and Butterworth filters response to narrowband noise in order to find a new ways to increase their immunity to noise. MATLAB Simulink Software has been used as a simulations environment.

Stochastic Time Response and Ultimate Noise Performance of Adsorption-Based Microfluidic Biosensors.

In order to improve the interpretation of measurement results and to achieve the optimal performance of microfluidic biosensors, advanced mathematical models of their time response and noise are needed. The random nature of adsorption–desorption and mass transfer (MT) processes that generate the sensor response makes the sensor output signal inherently stochastic and necessitates the use of a stochastic approach in sensor response analysis. We present a stochastic model of the sensor time response, which takes into account the coupling of adsorption–desorption and MT processes. It is used for the analysis of response kinetics and ultimate noise performance of protein biosensors. We show that slow MT not only decelerates the response kinetics, but also increases the noise and decreases the sensor’s maximal achievable signal-to-noise ratio, thus degrading the ultimate sensor performance, including the minimal detectable/quantifiable analyte concentration. The results illustrate the significance of the presented model for the correct interpretation of measurement data, for the estimation of sensors’ noise performance metrics important for reliable analyte detection/quantification, as well as for sensor optimization in terms of the lower detection/quantification limit. They are also incentives for the further investigation of the MT influence in nanoscale sensors, as a possible cause of false-negative results in analyte detection experiments.

Low Noise Amplifier Design and Performance Analysis of RF Front-End for Narrow Band Receivers

This manuscript presents the low noise amplifier design and performance analysis of receiver RF front-end for narrowband wireless communications. The LNA is a central building block of the wireless receiver. A single-ended cascode CMOS LNA is purposeful for reconfigurable applications such as Wireless LAN. The scope of this manuscript is to design an LNA appropriate for wireless applications with improved performance metrics. The contributions of this paper are noise reduction and high gain using an inductive degeneration common source stage. The proposed LNA espouses the entire simulation results in the frequency band of 2.44GHz. The excellent Noise Figure obtained as 0.95dB; the preferable power gain (S21) is 17dB, also the results of P-1dB of -17.3dBm, IIP3 of -10.7dBm at 2.44GHz, respectively. However, the perfect input and output matching network is achieved with proper reverse shielding and excellent stability.

Monolithically Integrated Parametric Mixers With Time-Varying Transmission Lines (TVTLs)

Mixers are frequency conversion devices that are widely used in radio applications. This article presents an in-depth theoretical study on the parametric mixing and amplification performance of the time-varying transmission lines (TVTLs) and utilizes the concept to design two TVTL parametric mixers on a commercially available InGaP HBT process. Unlike traditional passive mixers, these parametric mixers can provide a mild conversion gain and achieve a relatively low-noise figure. For the traveling-wave TVTL, the theory of the parametric mixing with the single-sideband condition is reviewed and compared with the double-sideband mixing case. The noise performance analysis shows that the noise figure of the TVTL can be made arbitrarily low to the quantum noise limit through the input reactive termination. The theory serves as a guideline for the design of MMIC parametric mixers. Measurement results have shown that the MMIC traveling-wave TVTL can achieve a maximum of 2.1-dB conversion gain. The mean noise figure was 2.7 dB within the measured frequency band. For the reflective TVTL parametric mixer, the conversion gain and the pump power consumption can be significantly improved. The noise figure, however, is degraded due to the multiple reflections created in the matching circuit. These conclusions are supported by theoretical analyses, ADS harmonic balance simulations, and experiments in this article.

Thermal noise performance analysis for dual binary phase‐shift keying tracking of standard BOC signals

Among the existing binary offset carrier (BOC) signal receiving technologies, the dual binary phase-shift keying tracking (DBT), originally designed for alternate BOC (AltBOC) modulated Galileo E5 signal and then extended to standard BOC signals, has its unique characteristics. It incorporates both single-band and dual-band processing schemes into a unified and simple structure to meet both requirements of improving ranging precision and anti-jamming. However, in this study, the authors propose that it is problematic to directly extend the DBT technique from the AltBOC signal to the standard BOC signal. The root cause of this problem lies in the fact that the cross-correlation functions between the received standard BOC signal and the local replicas in the upper and lower sidebands are not an ideal correlation triangle as the AltBOC case, but with some ripples. This leads to more complex behaviours when the DBT technique is applied to standard BOC signals. The rigorous theoretical analysis of this technique is given in respect of thermal noise performance in this study, which can be used not only to optimise the tracking loop parameters of DBT but also to compare the tracking performance of DBT and other tracking technologies.

Performance Analysis of Laser Phase Noise Compensated COOFDM System

AbstractOrthogonal Frequency Division Multiplexing along with the coherent detection and spectrally efficient modulation formats is a promising solution for long haul and high speed communication systems. Although they offer significant advantages which make them suitable for high speed and long haul communication systems they all are susceptible to phase noise. In this paper a combination of RF-pilot-based approach followed by pilot-based equalization approach is used for laser phase noise compensation. The various parameters such as drive voltage, bias voltage and extinction ratio are optimized to get the optimum performance from the proposed scheme. The designed system is then analyzed in terms of Symbol Error Rate (SER), constellation diagrams and error vector magnitude using various types of Quadrature Amplitude Modulation (QAM) formats.

Photographic Noise Performance Measures Based on RAW Files Analysis of Consumer Cameras

Photography is being benefited from the huge improvement in CMOS image sensors. New cameras extend the dynamic range allowing photographers to take photos with a higher quality than they could imagine one decade ago. However, the existence of different technologies make more complicated the photographic analysis of how to determine the optimal camera exposure settings. In this paper, we analyze how the different noise models are translated to different signal to noise S N R curve patterns and which factors are relevant. In particular, we discuss profoundly the relationships between exposure settings (shutter speed, aperture and ISO). Since a fair comparison between cameras can be tricky because of different pixel size, sensor format or ISO scale definition, we explain how the pixel analysis of a camera can be translated to a more helpful universal photographic noise measure based on human perception and common photography rules. We analyze the RAW files of different camera models and show how the noise performance analysis ( S N R and dynamic range) interact with photographer’s requirements.

Shallow Extension Engineered Dual Material Surrounding Gate (SEE-DM-SG) MOSFET for improved gate leakages, analysis of circuit and noise performance

The leakages in off state, particularly Gate Induced Drain Leakage (GIDL) has been addressed and reduced by proposing a Shallow Extension Engineered Dual Material Surrounding Gate (SEE-DM-SG) MOSFET. The shallow extensions create an insulating layer, which acts as a diffusion stopper and thereby suppresses the off state leakages. It is done by comparing the off-state performance of SEE-DM-SG MOSFET with Dual Metal Surrounding Gate (DM-SG) MOSFET and Surrounding Gate (SG) MOSFET. GIDL current is being reduced to an order of 10−12 A. Drain Induced Barrier Lowering (DIBL) has been curtailed to a greater extent in SEE-DM-SG MOSFET when compared with DM-SG MOSFET and SG MOSFET. GIDL has been extensively investigated for different drain voltages and temperatures; in order to study their impact on it. It was so found that GIDL was minimal for SEE-DM-SG MOSFET under different bias and temperature conditions. Arrhenius plot has also been plotted and deeply investigated as it instigates the GIDL activation energy (EA). It has been so found that SEE-DM-SG MOSFET poses higher EA and thereby suggests minimal BTBT (Band To Band Tunneling). So as to enhance the device applicability for low noise amplifier, the noise performance of SEE-DM-SG MOSFET has also been deeply investigated. Noise conductance (NC) and Noise Figure (NF) have been significantly curtailed in SEE-DM-SG MOSFET over DM-SG and SG MOSFET. A CMOS inverter has also been designed using SEE-DM-SG MOSFET and the output characteristics have also been compared for the aforesaid device architectures and higher Noise Margin has been observed in SEE-DM-SG MOSFET, making it more immune to noise.

Performance Analysis of Noise in Dual Halo Dual Dielectric Triple Material Surrounding Gate MOSFET for RF Applications

Performance Analysis of Noise in Dual Halo Dual Dielectric Triple Material Surrounding Gate MOSFET for RF Applications