Noise Coupling Research Articles

Minimizing Timing Jitter’s Impact on Ground-Penetrating Radar Array Coupling Signals

This article presents a novel investigation into the effect of receiver timing jitter on the quality of imaging of ground-penetrating radar systems. We explicitly show the impact of timing jitter throughout an entire example processing pipeline. The process of coupling removal in systems whose receivers have a random Gaussian-distributed jitter with a high standard deviation leaves randomly distributed residue in the radar image. This residue, called jitter-induced coupling noise, extends even into the expected target domain which may cause false alarms. This residue approximately follows a sum of Gaussian and Gamma distributions based on the higher order derivatives of the coupling signal. Once migrated to create an image, the coupling residue is best described by a Weibull distribution. We show that simple filtering does not remove enough residue and propose two preventative design specifications called the linear slope and migrated probability specifications. Antenna and system designers should use these specifications to assess the true severity of coupling signals in a given jitter environment.

An extensive survey on reduction of noise coupling in TSV based 3D IC integration

3D Integration technology is probably the best methodologies among others which suits CMOS applications with in various layers of devices are stacked with high thickness interconnects between the layers. In 3D IC structure electrical and thermal models are introduced for the interface between Through-Silicon-Via’s (TSV’s). TSV’s can be used to enable the 3-D platform; however this TSV’s will represent additional concerns. TSV-to-substrate and TSV-to-TSV noise coupling is assessed inside the 3-D IC’s. A vertical TSV’s design is proposed to reduce the area per TSV, capacitive coupling and effective inductance as compared with the other classical design patterns. TSV’s and substrate noise coupling is one of the major drawbacks in 3D IC. Some of the researchers have tried to overcome the problems in TSV based 3D IC due to noise coupling using different models, materials and different circuit techniques. This paper shows the complete road map for the noise coupling reduction in future IC integration.

Collective behavior of a nearest neighbor coupled system in a dichotomous fluctuating potential

In this study, the collective and stochastic resonance (SR) behavior of a stochastic nearest neighbor coupled system in a dichotomous fluctuating potential driven by a periodic force are investigated. The exact conditions of stability, synchronization and SR of the system are given analytically and verified by a numerical algorithm. We find that the final dynamic behaviors of the system are the results of the synergy of the coupled system, noise and external periodic force: the stationary regime criterion is only related to the noise parameters and system potential parameter; the synchronization criterion is related to the number of particles, coupling strength, noise parameters and system potential parameter. Furthermore, for the stationary regime, all particles synchronously move with their mean field and show SR phenomenon. For the non-stationary regime, the power-law distribution is observed when the synchronization criteria is satisfied.

Tilt-to-length noise coupled by wavefront errors in the interfering beams for the space measurement of gravitational waves.

The space-based gravitational wave detection programs, like the Laser Interferometer Space Antenna (LISA) or the Taiji program, aim to detect gravitational waves in space with a triangular constellation of three spacecraft. The unavoidable jitters of the spacecraft and the pointing will couple with the misalignment of the interfering beams into the longitudinal path length readout. This effect is called tilt-to-length (TTL) coupling, which is one of the keys to achieving the required measuring accuracy of 1pm/Hz. In terms of two phase definitions (the LISA Pathfinder (LPF) signal and the Average Phase (AP) signal), we implement the comprehensive theoretical analysis concerning the effect of aberrations on TTL coupling noise. In addition, we analytically derive that the proper lateral shift of the interfering beams relative to the detector can partly cancel out the TTL noise coupled with aberrations, especially coma and trefoil aberrations for the AP signal. Based on the above results, the meaningful guidance can be provided for the design and construction of the optical system in LISA or Taiji.

Higher-order and long-range synchronization effects for classification and computing in oscillator-based spiking neural networks

In the circuit of two thermally coupled VO2 oscillators, we studied a higher order synchronization effect, which can be used in object classification techniques to increase the number of possible synchronous states of the oscillator system. We developed the phase-locking estimation method to determine the values of subharmonic ratio and synchronization effectiveness. In our experiment, the number of possible synchronous states of the oscillator system was twelve, and subharmonic ratio distributions were shaped as Arnold's tongues. In the model, the number of states may reach the maximum value of 150 at certain levels of coupling strength and noise. The long-range synchronization effect in a one-dimensional chain of oscillators occurs even at low values of synchronization effectiveness for intermediate links. We demonstrate a technique for storing and recognizing vector images, which can used for reservoir computing. In addition, we present the implementation of analog operation of multiplication, the synchronization based logic for binary computations, and the possibility to develop the interface between spike neural network and a computer. Based on the universal physical effects, the high order synchronization can be applied to any spiking oscillators with any coupling type, enhancing the practical value of the presented results to expand spike neural network capabilities.

Identification of abnormal conditions in high-dimensional chemical process based on feature selection and deep learning

Abstract Identification of abnormal conditions is essential in the chemical process. With the rapid development of artificial intelligence technology, deep learning has attracted a lot of attention as a promising fault identification method in chemical process recently. In the high-dimensional data identification using deep neural networks, problems such as insufficient data and missing data, measurement noise, redundant variables, and high coupling of data are often encountered. To tackle these problems, a feature based deep belief networks (DBN) method is proposed in this paper. First, a generative adversarial network (GAN) is used to reconstruct the random and non-random missing data of chemical process. Second, the feature variables are selected by Spearman's rank correlation coefficient (SRCC) from high-dimensional data to eliminate the noise and redundant variables and, as a consequence, compress data dimension of chemical process. Finally, the feature filtered data is deeply abstracted, learned and tuned by DBN for multi-case fault identification. The application in the Tennessee Eastman (TE) process demonstrates the fast convergence and high accuracy of this proposal in identifying abnormal conditions for chemical process, compared with the traditional fault identification algorithms.

Large, Tunable Valley Splitting and Single-Spin Relaxation Mechanisms in a Si / Six Ge1−x Quantum Dot

Valley splitting is a key figure of silicon-based spin qubits. Quantum dots in Si/SiGe heterostructures reportedly suffer from a relatively low valley splitting, limiting the operation temperature and the scalability of such qubit devices. Here, we demonstrate a robust and large valley splitting exceeding 200 $\mu$eV in a gate-defined single quantum dot, hosted in molecular-beam epitaxy-grown $^{28}$Si/SiGe. The valley splitting is monotonically and reproducibly tunable up to 15 % by gate voltages, originating from a 6 nm lateral displacement of the quantum dot. We observe static spin relaxation times $T_1>1$ s at low magnetic fields in our device containing an integrated nanomagnet. At higher magnetic fields, $T_1$ is limited by the valley hotspot and by phonon noise coupling to intrinsic and artificial spin-orbit coupling, including phonon bottlenecking.

Compact Simulation of Chip-to-Chip Active Noise Coupling on a System PCB Board

A chip-to-chip active noise coupling demonstrator integrates two identical complementary metal oxide silicon (CMOS) chips on a printed circuit board (PCB), where each chip has the capability of power noise generation by CMOS shift resister array circuits (noise source; NS) and also power noise measurements by on-chip voltage monitoring circuits (OCM). For establishing the noise aware design strategy and methodology, a full-system level noise coupling simulation technique is evaluated on the demonstrator representing a multi-chip mixed-signal PCB. In an experimental scenario, an IC chip (Aggressor IC) operates the NS to generate power noise and the OCM measures the voltage fluctuation of the power delivery network (PDN) within the chip. On the other hand, another IC (Victim IC) holds the NS in no operation while uses the OCM to monitor its PDN voltage fluctuation caused by the conducted noise from the aggressor IC. For the verification of simulation accuracy, two chip power models (CPM), package wire models, discrete de-cap models and a single PCB model are combined into a chip-package-system (CPS) integrated model. The simulation was performed in about 2 hours for CPS integrated noise simulation including S-parameter extraction of the PCB. It is demonstrated that the full-system model with the two CPMs successfully simulates chip-to-chip active noise coupling, namely noise propagation from internal circuits of an aggressor chip to those on a victim chip. The chip-to-chip noise coupling simulation exhibited good agreements with measurements in case studies. The simulation methodology enables conductive noise aware design for multi-chip mixed-signal PCB in its design stage.

Machine-learning nonstationary noise out of gravitational-wave detectors

Signal extraction out of background noise is a common challenge in high precision physics experiments, where the measurement output is often a continuous data stream. To improve the signal to noise ratio of the detection, witness sensors are often used to independently measure background noises and subtract them from the main signal. If the noise coupling is linear and stationary, optimal techniques already exist and are routinely implemented in many experiments. However, when the noise coupling is non-stationary, linear techniques often fail or are sub-optimal. Inspired by the properties of the background noise in gravitational wave detectors, this work develops a novel algorithm to efficiently characterize and remove non-stationary noise couplings, provided there exist witnesses of the noise source and of the modulation. In this work, the algorithm is described in its most general formulation, and its efficiency is demonstrated with examples from the data of the Advanced LIGO gravitational wave observatory, where we could obtain an improvement of the detector gravitational wave reach without introducing any bias on the source parameter estimation.

MTL-based modeling and analysis of the effects of TSV noise coupling on the power delivery network in 3D ICs

With the application of heterogeneous integration and advanced packaging technologies, the use of through-silicon vias (TSVs) to deliver the power supply has become popular in the design of stacked chips in three-dimensional integrated circuits. High-density vertical interconnections offer higher speed and bandwidth, but the electromagnetic coupling effect among TSVs becomes more serious. Therefore, investigation of the noise coupling among TSVs and analysis of its impact on the power supply become important considerations. An analytical model based on the theory of multiconductor transmission lines (MTLs) is presented herein to discuss such TSV noise coupling. The method can accurately and quickly estimate the noise coupling coefficient among a large number of TSVs and offers good practicability for similar structures and even the TSVs of complex structures. Further, the influence of TSV noise coupling and simultaneous switching noise from switching circuits on the supplied power voltage is discussed. Finally, the parameters of an actual Intel chip are taken as an example to analyze the supplied power voltage that reaches complementary metal–oxide–semiconductor (CMOS) circuits through the three-dimensional (3D) power distribution network after considering the power supply noise. The presented model is validated by comparing the calculation results with those obtained from a full-wave simulator. The runtime and memory consumption requirements are lower than those of the full-wave simulator.

Dynamic Frequency Scaling Aware Opportunistic Through-Silicon-Via Inductor Utilization in Resonant Clocking

LC resonant clock is a viable option for low power on-chip clock distributions. A major limiting factor to its implementation is the large area overhead due to the use of conventional spiral inductors. On the other hand, idle through-silicon-vias (TSVs) in 3-D integrated circuits (3-D ICs) can form vertical inductors with minimal footprint and have little noise coupling with horizontal traces, particularly suitable for the application of LC resonant clock. However, due to the strict constraints on the location of idle TSVs, the use of the TSV inductor is constrained by its location, inductance, and quality factor. The problem is further complicated by dynamic frequency scaling (DFS), where the resonant tanks need to accommodate multiple clock frequencies. Moreover, these TSV inductors can be in any orientation with any distance apart, thereby causing complicated coupling effects. In this paper, we first present a novel scheme to opportunistically use idle TSVs to form inductors in LC resonant clock of 3-D ICs for maximum power reduction in clock-distribution network (CDN) at a fixed frequency, and then extend it to DFS schemes. Experimental results on a few industrial designs for the resonant CDNs operated at a fixed frequency of 3 GHz show that the power consumption is reduced by up to 47.9% compared with the conventional CDNs without resonant clocking. In addition, for the resonant CDNs with DFS scheme, the power consumption reduced by up to 42.3%, 39.0%, 38.3%, 34.3%, and 28.6% at 3, 2.5, 2, 1.5, and 1 GHz frequency, respectively, compared with the CDNs without resonant clocking. When compared with CDNs with conventional spiral inductors, our scheme with TSV inductors can reduce the inductor footprint by up to $6.30 \times$ with the same power consumption.

Incorporating two coupling noises into a nonlinear competitive system with saturation effect

In this paper, a novel stochastic two-species competitive system with saturation effect is formulated, in which there exist two noise resources and their coupling mode is relatively complex and every noise source has effect on the intrinsic growth rates of both species. With the help of some suitable Lyapunov functions, sufficient conditions for stochastic permanence are established as exponential extinction, extinction, permanence in time average and asymptotic pathwise estimation of system. The effect of coupling noise on the asymptotic behaviors of the populations is shown.

Noise performance improvement in 3D IC integration utilizing different dielectric materials

Semiconductor Industries are mainly facing problems by using planar integration (2D IC) in order to overcome the paradigm shift has been adopted as vertical IC integration so called 3D IC. It not only provides higher bandwidth, higher system performance, but also consumes less power with system scaling. 3D IC has an ability to coordinate IC chips by stacking them vertically and electrically associated utilizing TSV's (Through Silicon Via). By utilizing TSV's in 3D IC, TSV noise coupling is one of the vital factors for the system performance aspects. TSV's play major role in carrying the electrical signal between the IC’s of 3D integrated structures. Noise coupling is the major drawback between the signal carrying TSV’s (ETSV) and victim TSV’s. In this work, we have shown better electrical integrity by reducing the noise coupling from TSV to Silicon substrate by essentially changing the CMOS compatible dielectric materials as liner structures. In addition to this performance of various proposed structures are analyzed and verified under different parameters like electrical signal and at high frequencies. Also, the noise coupling analysis has been studied for Electrical TSV’s (ETSV), TTSV (Thermal Through Silicon Via) and heat source. Finally, our work shows liner material Teflon AF1600 shows comparably better noise coupling performance for all the proposed models even at higher frequencies like THz.

Simplistic approach to alleviate noise coupling issues in 3D IC integration

Through-silicon-via (TSV) technology has emerged as the key technology to enable 3D IC integration. 3D integration is seen as the leading candidate, which can help in sustaining Moore’s Law to future IC technology nodes. It clearly set a benchmark to the IC industry due to its tremendous benefits in performance, data bandwidth, and supports heterogeneous integration. In 3D IC structure TSV’s are used to carry the overall electrical signal between the layers. The major drawback in the TSV based 3D integration is noise coupling between aggressive (electrical signal carrying TSV; ETSV) and victim TSV’s (ground). It can be reduced by creating very good isolation between TSV’s and Si substrate by using different liner materials around TSV’s. In this work, we have addressed various TSV models to reduce noise coupling between the TSV’s. The models we have studied are single layer model and stacked layers of liner model. Apart from this we have studied how the core materials in the TSV reduces noise coupling between aggressive and victim TSV’s. Also, we have shown the high frequency study for proposed models. Finally, our work shows single layer model with Crystalline-Germanium is comparably better noise coupling reduction even at higher frequency.

Extinction and stationary distribution of a competition system with distributed delays and higher order coupled noises.

A stochastic two-species competition system with saturation effect and distributed delays is formulated, in which two coupling noise sources are incorporated and every noise source has effect on two species' intrinsic growth rates in nonlinear form. By transforming the two-dimensional system with weak kernel into an equivalent four-dimensional system, sufficient conditions for extinction of two species and the existence of a stationary distribution of the positive solutions to the system are obtained. Our main results show that the two coupling noises play a significant role on the long time behavior of system.

Noise Performance Improvement In Future IC Integration using Perylene-N As Dielectric Material

Ever-growing consumer demand for smaller and faster devices opens up to think the semiconductor industries about another direction of improvement during IC integration as long run metal wires not only reduces the form factor of the system but also decreases the system performance by creating RC delay which in turn reduces the bandwidth during communication. In order to improve the system performance the devices must be interconnected vertically known as 3D IC integration. In this emerging technique, different modules are mounted on different layers with Si substrate and these layers are placed one on other. TSV’s (Through Silicon Via or Through Substrate Via) are the basic building blocks of the 3D ICs which are playing an important role to create high performance electrical path between thin IC chips. TSV’s carries the entire electrical signal between the layers of 3D structure. Major drawback is poor electrical signaling due to the noise coupling between signal carrying TSV’s(aggressive TSV’s) and ground TSV’s(victim TSV’s).Therefore there is a strong need of isolation between Si substrate and TSV’s with proper liner materials and structures. Perylene-N is one of the most promising dielectric material for less area consumption and less power consumption. In this paper, we compared the results for Perylene-N and conventional SiO2 liner for ETSV’s. The performance of this structure is analyzed and verified under different parameters to reduce the noise coupling. In this structure dielectric-metal-dielectric are arranged around the Copper TSV. The achieved result shows that more noise coupling is reduced by using Perylene-N as dielectric material as compared with conventional SiO2. Furthermore, Perylene-N shows 33 dB improvements in noise coupling performance at THz frequencies which is verified and validated as well in this work.

Two scenarios for the onset and suppression of collective oscillations in heterogeneous populations of active rotators.

We consider the macroscopic regimes and the scenarios for the onset and the suppression of collective oscillations in a heterogeneous population of active rotators composed of excitable or oscillatory elements. We analyze the system in the continuum limit within the framework of Ott-Antonsen reduction method, determining the states with a constant mean field and their stability boundaries in terms of the characteristics of the rotators' frequency distribution. The system is established to display three macroscopic regimes, namely the homogeneous stationary state, where all the units lie at the resting state, the global oscillatory state, characterized by the partially synchronized local oscillations, and the heterogeneous stationary state, which includes a mixture of resting and asynchronously oscillating units. The transitions between the characteristic domains are found to involve a complex bifurcation structure, organized around three codimension-two bifurcation points: a Bogdanov-Takens point, a cusp point, and a fold-homoclinic point. Apart from the monostable domains, our study also reveals two domains admitting bistable behavior, manifested as coexistence between the two stationary solutions or between a stationary and a periodic solution. It is shown that the collective mode may emerge via two generic scenarios, guided by a saddle-node of infinite period or the Hopf bifurcation, such that the transition from the homogeneous to the heterogeneous stationary state under increasing diversity may follow the classical paradigm, but may also be hysteretic. We demonstrate that the basic bifurcation structure holds qualitatively in the presence of small noise or small coupling delay, with the boundaries of the characteristic domains shifted compared to the noiseless and the delay-free case.

Fixation properties of rock-paper-scissors games in fluctuating populations

Rock-paper-scissors games metaphorically model cyclic dominance in ecology and microbiology. In a static environment, these models are characterized by fixation probabilities obeying two different “laws” in large and small well-mixed populations. Here, we investigate the evolution of these three-species models subject to a randomly switching carrying capacity modeling the endless change between states of resources scarcity and abundance. Focusing mainly on the zero-sum rock-paper-scissors game, equivalent to the cyclic Lotka–Volterra model, we study how the coupling of demographic and environmental noise influences the fixation properties. More specifically, we investigate which species is the most likely to prevail in a population of fluctuating size and how the outcome depends on the environmental variability. We show that demographic noise coupled with environmental randomness “levels the field” of cyclic competition by balancing the effect of selection. In particular, we show that fast switching effectively reduces the selection intensity proportionally to the variance of the carrying capacity. We determine the conditions under which new fixation scenarios arise, where the most likely species to prevail changes with the rate of switching and the variance of the carrying capacity. Random switching has a limited effect on the mean fixation time that scales linearly with the average population size. Hence, environmental randomness makes the cyclic competition more egalitarian, but does not prolong the species coexistence. We also show how the fixation probabilities of close-to-zero-sum rock-paper-scissors games can be obtained from those of the zero-sum model by rescaling the selection intensity.

Composite anti-disturbance control for stochastic systems with multiple heterogeneous disturbances and input saturation

This paper develop a novel composite anti-disturbance control (CADC) method for a class of stochastic nonlinear systems in which input saturation and multiple heterogeneous disturbances occur. The disturbances include additive white noise, multiplicative white noise and modeled disturbances with coupling of energy-limited white noise and state signals. The input saturation item of system is approximated by the polytopic bounding method. In order to estimate the modeled disturbances, a novel stochastic saturating disturbance observer (SSDO) is designed. The CADC scheme is presented by integrating SSDO with convex hull expression of saturated linear feedback law, such that the superior anti-disturbance performance to be achieved while overcoming the effects of input saturation. Finally, the validity and usability of the developed scheme are testified by the numerical simulation and practical application example.

Noise Performance Improvement in Future IC Integration using Perylene-N as Dielectric Material

Ever-growing consumer demand for smaller and faster devices opens up to think the semiconductor industries about another direction of improvement during IC integration as long run metal wires not only reduces the form factor of the system but also decreases the system performance by creating RC delay which in turn reduces the bandwidth during communication. In order to improve the system performance the devices must be interconnected vertically known as 3D IC integration. In this emerging technique, different modules are mounted on different layers with Si substrate and these layers are placed one on other. TSV’s (Through Silicon Via or Through Substrate Via) are the basic building blocks of the 3D ICs which are playing an important role to create high performance electrical path between thin IC chips. TSV’s carries the entire electrical signal between the layers of 3D structure. Major drawback is poor electrical signaling due to the noise coupling between signal carrying TSV’s(aggressive TSV’s) and ground TSV’s(victim TSV’s).Therefore there is a strong need of isolation between Si substrate and TSV’s with proper liner materials and structures. Perylene-N is one of the most promising dielectric material for less area consumption and less power consumption. In this paper, we compared the results for Perylene-N and conventional SiO2 liner for ETSV’s. The performance of this structure is analyzed and verified under different parameters to reduce the noise coupling. In this structure dielectric-metal-dielectric are arranged around the Copper TSV. The achieved result shows that more noise coupling is reduced by using Perylene-N as dielectric material as compared with conventional SiO2. Furthermore, Perylene-N shows 33 dB improvements in noise coupling performance at THz frequencies which is verified and validated as well in this work.