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This paper provides theoretical insight on how circular Schottky photodiodes in bulk CMOS can be optimized for certain integrated receiver applications. An optimal photodiode size is analytically demonstrated and the effects of a metal plate reflector are simulated using a transfer-matrix method, both for frontside and backside illumination. Finally, a distributed circuit model is presented, which deviates from the classical lumped model for large photodiodes or sheet resistances. The presented methodologies can also be extended to other types of photodetectors.

The retrosplenial cortex plays a role in associating familiar environmental contexts with appropriate motor actions., During navigation, animals often use recognition of familiar environmental contexts to guide motor action selection. The retrosplenial cortex (RSC) receives inputs from both visual cortex and subcortical regions required for spatial memory and projects to motor planning regions. However, it is not known whether RSC is important for associating familiar environmental contexts with specific motor actions. We test this possibility by developing a task in which motor trajectories are chosen based on the context. We find that mice exhibit differential predecision activity in RSC and that optogenetic suppression of RSC activity impairs task performance. Individual RSC neurons encode a range of task variables, often multiplexed with distinct temporal profiles. However, the responses are spatiotemporally organized, with task variables represented along a posterior-to-anterior gradient along RSC during the behavioral performance, consistent with histological characterization. These results reveal an anatomically organized retrosplenial cortical circuit for associating environmental contexts with appropriate motor outputs.

International audience; This paper investigates an innovative negative group delay (NGD) theory of ''li'' geometrical shape topology. The li-topology is an outstandingly simple and fully distributed circuit comprised of a coupled line (CL). The li S-parameter model taking into account the CL coupling coefficient, delay and attenuation is established. The NGD analysis showing the possibility to generate NGD condition with respect to the li topology parameters is developed. The NGD characteristics as NGD value, center frequency, bandwidth, transmission and reflection coefficient are expressed. The li-NGD theory is validated with two proofs-of-concept implemented in microstrip technology. Calculated models, simulations and measurements are in good correlation. As expected, bandpass NGD presenting center frequency at approximately 2.56 GHz and 0.92 GHz with NGD level of approximately −0.9 ns and −3.7 ns were realized with the small and large li prototypes. Outstanding time-domain analyses explaining the bandpass NGD meaning, with innovatively low attenuation output, were also presented. The time-domain results highlight li-output pulse signal envelopes in time advance without violating the causality. INDEX TERMS Distributed circuit, li-topology, microwave theory, negative group delay (NGD), S-matrix modelling.

Electroluminescence (EL) images with absolute photon emissions from Cu(In, Ga)Se2 (CIGS) solar cells were obtained under different forward current injections, with the spatially distributed EL emission becoming non-uniform as the current density gradually increases. A distributed two-diode electrical three-dimensional model was established which simulated the dark current density-voltage curves and the absolute EL images of the CIGS solar cells very well. Then, the resistive effects were analyzed using this model and simulation results show that the sheet resistance of the transparent conductive oxide (TCO) layer dominates the non-uniform distribution of the EL emission in the studied CIGS thin-film solar cells. The effect of the sheet resistance of the TCO and the series resistance of the micro-diode on the EL variations is found to become obvious under high-current-injection conditions, whereas the effect of shunt resistance of the micro-diode on the EL variations becomes more obvious under low-resistance value or low-current-injection conditions.

Major depressive disorder is a common and disabling disorder with high rates of treatment resistance. Evidence suggests it is characterized by distributed network dysfunction that may be variable across patients, challenging the identification of quantitative biological substrates. We carried out this study to determine whether application of a novel computational approach to a large sample of high spatiotemporal resolution direct neural recordings in humans could unlock the functional organization and coordinated activity patterns of depression networks. This group level analysis of depression networks from heterogenous intracranial recordings was possible due to application of a correlational model-based method for inferring whole-brain neural activity. We then applied a network framework to discover brain dynamics across this model that could classify depression. We found a highly distributed pattern of neural activity and connectivity across cortical and subcortical structures that was present in the majority of depressed subjects. Furthermore, we found that this depression signature consisted of two subnetworks across individuals. The first was characterized by left temporal lobe hypoconnectivity and pathological beta activity. The second was characterized by a hypoactive, but hyperconnected left frontal cortex. These findings have applications toward personalization of therapy.

A transient study of bandpass (BP) negative group delay (NGD) function is devoted in this paper. The transient analysis is applied to an original topology of NGD barcode-shape microstrip circuit. The performed investigation explains how to realize the transient analysis of tri-band NGD circuit. The time-domain (TD) parametrization of the test is established from the BP-NGD specifications of the circuit under test (CUT) based on the S-parameter model. The input signal is a Gaussian pulse characterized in function of the NGD bandwidth (BW) and center frequency. The feasibility of the BP-NGD transient study is illustrated with experimentation based on ultra-wide band (UWB) pulse generator. As proof-of-concept, barcode NGD circuit exhibiting tri-band NGD value-center frequency-bandwidth, (−5.9 ns, 2.128 GHz, 20 MHz), (−7.4 ns, 2.3 GHz, 14 MHz) and (−4.8 ns, 2.42 GHz, 14 MHz) has been fabricated and tested. The transient simulations and experiences confirm that the output signal envelopes of the barcode NGD prototype present leading and tailing edges in time-advance of input ones when the carrier frequency is set equal to the NGD center frequency.

During navigation, animals often use recognition of familiar environmental contexts to guide motor action selection. The retrosplenial cortex (RSC) receives inputs from both visual cortex and subcortical regions required for spatial memory, and projects to motor planning regions. However, it is not known whether RSC is important for associating familiar environmental contexts with specific motor actions. Here, we test this possibility by developing a task in which trajectories are chosen based on the context. We find that mice exhibit differential pre-decision activity in RSC, and that optogenetic suppression of RSC activity impairs task performance. Individual RSC neurons encode a range of task variables, often multiplexed with distinct temporal profiles. However, the responses are spatiotemporally organized, with task variables represented along a posterior-to-anterior gradient along RSC during the behavioral performance, consistent with histological characterization. These results reveal an anatomically-organized retrosplenial cortical circuit for associating environmental contexts to appropriate motor outputs.

The statement of overheating of honey during the processing is very important in quality characterization of honey products. Four various Hungarian acacia honeys from different places were hold in water bath of 35, 40, 50, 60, and 80 °C 0,5, 4 and 24 h. After heating the honeys were cooled down to room temperature. The electrical impedance spectrum of honeys before and after heating were measured by precision LCR meters in frequency range from 30 Hz up to 30 MHz at 1 V voltage with Ag/AgCl electrodes at room temperature (22 °C). The measured impedance spectra after open and short correction were approached with a model consisting of a distributed circuit element in serial connection with a resistance. The parameters of this model were determined. The resistance of the distributed circuit element was decreased after heat treatment for all honeys. After more detailed investigation this parameter can be used for detecting the earlier heating of honey products.

Wave digital filters are derived from a wave description of an analog filter with distributed circuit elements. A wave description allow us to define a pseudo-power concept in the z-domain. If the analog filter is designed using the maximum power transfer concept, then the wave digital filter will inherit the sensitivity properties and it also lead to techniques to suppress parasitic oscillations. We furthermore discuss basic building blocks and basic resonance circuits and their wave digital counterparts.

We report the non-uniform distributed confocal travelling-wave amplifier (gyro-Twa)for high-gain operation at the first time. The circuit applies a long section with heavy circuit loss to the phase-modulation region for stability consideration, whilst utilizing a taper circuit that attached to a short wide-mirror section in the nonlinear-interaction region to maximum the output power. Nonlinear theory calculations predicted that the W-band gyro-amplifier operates at HE 04 mode is capable of producing an output power of above 100 kW and a saturated gain of more than 60 dB within 93–97 GHz.

International audience; This paper presents a new radio frequency channel access method to a radio frequency (RF) interconnect for intra‐chip communications. The method overcomes the undesired effects that come from multiple connections in classical methods. It is based on an active access, through transistors associated in a distributed topology. This leads to better properties in terms of reflection and transmission coefficients along the transmission line. This approach is validated by making a deep comparison with the basic existing access methods (eg, direct and capacitive). Measurements on a test circuit using the 0.25 μm SiGe BiCMOS technology confirm the good performance of the proposed access.

The authors of this paper proposed an effective method applied to frequency response interpretation in low frequency range and mechanical failure diagnosis support based on measurements and analysis of a physical lumped component transformer circuit. To extend the interpretation until medium frequencies where mechanical failures influence most, this paper presents a novel approach on determining parameters in a physical distributed component circuit. The most important contribution of this paper is the possibility of determination of electrical parameters in the distributed circuit without knowing detailed knowledge of the transformer construction, which has been a challenge so far. In addition, the application capability of the distributed circuit in diagnosis of several mechanical failures in a distribution transformer is also investigated.

Working memory (WM) and decision-making (DM) are fundamental cognitive functions involving a distributed interacting network of brain areas, with the posterior parietal cortex (PPC) and prefrontal cortex (PFC) at the core. However, the shared and distinct roles of these areas and the nature of their coordination in cognitive function remain poorly understood. Biophysically based computational models of cortical circuits have provided insights into the mechanisms supporting these functions, yet they have primarily focused on the local microcircuit level, raising questions about the principles for distributed cognitive computation in multiregional networks. To examine these issues, we developed a distributed circuit model of two reciprocally interacting modules representing PPC and PFC circuits. The circuit architecture includes hierarchical differences in local recurrent structure and implements reciprocal long-range projections. This parsimonious model captures a range of behavioral and neuronal features of frontoparietal circuits across multiple WM and DM paradigms. In the context of WM, both areas exhibit persistent activity, but, in response to intervening distractors, PPC transiently encodes distractors while PFC filters distractors and supports WM robustness. With regard to DM, the PPC module generates graded representations of accumulated evidence supporting target selection, while the PFC module generates more categorical responses related to action or choice. These findings suggest computational principles for distributed, hierarchical processing in cortex during cognitive function and provide a framework for extension to multiregional models.

This paper describes methods to utilize the multi-core PC as well as computers connected by internet to perform MOSFET circuit simulations. The Combining Simulation Method (CSM) is the used parallel algorithm. This paper also presents an automatic method to partition the simulation jobs in CSM. All proposed methods have been implemented and tested. Experimental results justify pleasing effects of proposed methods.

In this paper, we describe methods to utilize the multi-core CPU as well as computers connected by internet to perform large-scale MOSFET circuit simulations. That is, both distributed and parallel computing are utilized to do the simulation. Parallel Newton Relaxation and Combining Simulation Method (CSM) are our numerical tools to accomplish parallel and distributed computing respectively. We note that both coursed and fine grained parallel computing strategies are used in this paper. All proposed methods have been implemented and tested. Experimental results justify pleasing effects of all proposed methods.

Local inhomogeneity effects such as shunts, inhomogeneous sheet resistance and inhomogeneous recombination rate are typical phenomena for silicon wafer solar cells. Some widely used solar cell simulators (for example Sentaurus TCAD and PC1D) have limitations in modelling these effects, since they are, for practical reasons, often restricted either to only one or two dimensions, or to small scales. In this work, circuit modelling is used to simulate local inhomogeneity effects of a silicon wafer solar cell. A distributed circuit model has the advantage that it can take large-scale lateral transport of carriers into account. First, the method of constructing the distributed circuit model is described. Then some local inhomogeneities, such as local shunts and broken fingers, are introduced into the circuit model. Finally, the global I-V characteristics and voltage distribution of the modelled cell are calculated. It is found that local inhomogeneities have an influence on the efficiency of a solar cell, and that this kind of influence can be quantified by circuit modelling. For example, it was calculated that a broken finger reduced the fill factor of the simulated solar cell by about 1.1% relative, and local shunt reduced the fill factor by about 3.2% relative.

The design parameters of a buck converter are investigated based on ac small-signal design parameters such as open-loop, input-to-output and control-to-output transfer functions including distributed circuit parameters that account for PCB parasitics. It is demonstrated that the PCB effects neglected in a 2nd order model could affect the design parameters such as selection of switching frequency. The relations developed in this work are validated in the power design of an idustrial circuit and compared to the conventional 2nd order models.

An experimental procedure for measuring the drug absorbed by a biological tissue in laboratory emulation of dermatological topical treatments is proposed. Laboratory emulation is based on the analysis of the eggplant electrical reaction to the injection of drug. Eggplant and human tissue are both well modeled by a distributed circuit model described by the ColeCole empirical equation. An exploratory measurement campaign aimed at investigating the relationship between the injected drug amount and the measured impedance is reported. The basic ideas, the measurement system design, and the proposed measurement procedure are illustrated. Then, its feasibility is proved experimentally and the results of the metrological characterization are reported and discussed. Results point out that, by a “simple” measurement of the impedance module (and not a spectroscopy), the amount of injected drug can be assessed by acceptable uncertainty.

The Generalized Transmission Line Equations are employed to analyze the circuit parameters of the microstrip lines. The static distributed capacitances and inductances of non-uniform microstrip lines are extracted. By comparing the differences between the port’s S-parameters respectively obtained by the extracted static circuit parameters using circuit method and by the Method of Moment directly, the applicable frequency range of the extracted static distributed circuit parameters can be found. The results show that the extracted static circuit parameters can be used in a frequency band from DC up to millimeter wave.

The full-wave and circuit method are combined to be utilized to analyze the performance of the sinusoidal shaped microstrip bandstop filter. The static distributed circuit parameters of the filter are extracted with the full-wave electromagnetic method, then used to construct the equivalent circuit. The frequency domain performance of the sinusoidal shaped microstrip bandstop filter are obtained with the input and characteristic impedance calculated from the equivalent circuit. Owing to better agreement between the S parameters obtained with static circuit parameters and the measured results, the effectiveness of the distributed circuit parameters applied to predict the performance of microstrip filter is verified.

Middle-permittivity dielectric compositions are necessary to realize various distributed circuit components in Low temperature co-fired ceramics (LTCC) structures. In this study, we are reporting some dielectric compositions the permittivity range of which are in the range of 20–60. Various borosilicate-based glass compositions were added to two kinds of middle-k commercial dielectric compositions to get the densification temperatures of lower than 875 °C. The effects of the composition and the amount of borosilicate-based glass systems on the densification and the microwave properties were examined.

We present a method for simulating static domain formation in distributed negative differential resistance devices using a distributed circuit array model coupled with quantum transport simulations. This simulation method is applied to the case of a superlattice Bloch oscillator to ascertain the efficacy of electric field domain wall suppression by micro shunt side walls. Two independent simulation mechanisms using the same basic distributed circuit model are employed to separate simulation artifacts from true physical trends. Simulations are presented, suggesting that the presence of the micro shunt can suppress domain formation above a critical device bias voltage. The simulated dependence of this critical voltage on macroscopic device parameters is presented.

A new numerical model of microstrip transmission line circuits in terms of distributed circuit parameters is here illustrated. Based on full-wave electromagnetic results, the extraction methods of these distributed circuit parameters on different types of microstrip transmission line circuits are introduced. As a preparatory experiment, an improved CAD method using this model is tested on microstrip low-pass filter. Copyright © 2003 John Wiley & Sons, Ltd.

A method, electrical impedance spectroscopy (EIS), is introduced to study seed viability non-destructively. Snap bean (Phaseolus vulgaris L.) seeds were studied by EIS to determine the most sensitive EIS parameter(s) and the optimal range of moisture content (MC) for separation of viable and non-viable seeds. Hydrated seeds exhibited two impedance arcs in the complex plane at the frequency range from 60 Hz to 8 MHz, and impedance spectra of viable and non-viable seeds differed. The hydrated seeds were best-modelled by an equivalent electrical circuit with two distributed circuit elements in series with a resistor (Voigt model). Moisture content and seed viability had strong effects on the EIS parameters. The most sensitive EIS parameters for detecting the differences between viable and non-viable seeds were the capacitance log(C2), the resistance R2, the resistance ratio R2/R1 and the apex ratio, which all represent specific features of the impedance spectrum. The highest differentiation in the EIS parameters between the viable and non-viable seeds occurred in partially imbibed seeds between MC of 40 and 45% (fresh weight basis).

We characterized the near-interface traps (NITs) in SiO2/4H-SiC structures according to the distributed circuit model, which was originally proposed for Al2O3/InGaAs interface structures. We assumed that the NITs had an exponentially decaying distribution from the SiO2/4H-SiC interface into the oxide, rather than the uniform trap distribution of the conventional model. Using this model with the exponential NIT distribution as a basis, we successfully explained the frequency-dependent characteristics of both the capacitance and conductance in the strong-accumulation condition with reasonable physical parameters. We also observed that nitridation annealing over a long period of time significantly reduced the NIT density distribution.

With the increasing popularity of wearable computing devices, new sensing techniques that enable always-available interaction are highly demanded. In this paper, we propose Body RC, a novel body-based device using human body as lossy signal transmission medium. This device supports on-body interaction and body gesture recognition. In particular, Body RC recognizes the operations of on-body interaction and body gestures by analyzing the electrical properties when transmitting single high frequency analog signal through human body. We evaluate the capabilities and performance of Body RC through two controlled experiments showing robust classification of both on-body interaction and body gesture recognition. In addition, we design a real-time recognition system demonstrating the utility of our technique.