An experimental technique is described for observing the effects of switching transients in digital MOS circuits that perturb analog circuits integrated on the same die by means of coupling through the substrate Various approaches to reducing substrate crosstalk (the use of physical separation of analog and digital circuits, guard rings, and a low-inductance substrate bias) are evaluated experimentally for a CMOS technology with a substrate comprising an epitaxial layer grown on a heavily doped bulk wafer Observations indicate that reducing the inductance in the substrate bias is the most effective Device simulations are used to show how crosstalk propagates via the heavily doped bulk and to predict the nature of substrate crosstalk in CMOS technologies integrated in uniform, lightly doped bulk substrates, showing that in such cases the substrate noise is highly dependent on layout geometry A method of including substrate effects in SPICE simulations for circuits fabricated on epitaxial, heavily doped substrates is developed >

Experimental Results and Modeling Techniques for Substrate Noise in Mixed-Signal Integrated Circuits

Plasmons and magnetoplasmons in semiconductor heterostructures

Classification of power quality events – A review

Call admission control (CAC) is a key element in the provision of guaranteed quality of service (QoS) in wireless networks. The design of CAC algorithms for mobile cellular networks is especially challenging given the limited and highly variable resources, and the mobility of users encountered in such networks. This article provides a survey of admission control schemes for cellular networks and the research in this area. Our goal is to provide a broad classification and thorough discussion of existing CAC schemes. We classify these schemes based on factors such as deterministic/stochastic guarantees, distributed/local control and adaptivity to traffic conditions. In addition to this, we present some modeling and analysis basics to help in better understanding the performance and efficiency of admission control schemes in cellular networks. We describe several admission control schemes and compare them in terms of performance and complexity. Handoff prioritization is the common characteristic of these schemes. We survey different approaches proposed for achieving handoff prioritization with a focus on reservation schemes. Moreover, optimal and near-optimal reservation schemes are presented and discussed. Also, we overview other important schemes such as those designed for multi-service networks and hierarchical systems as well as complete knowledge schemes and those using pricing for CAC. Finally, the paper concludes on the state of current research and points out some of the key issues that need to be addressed in the context of CAC for future cellular networks. Copyright © 2005 John Wiley & Sons, Ltd.

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Call admission control in mobile cellular networks: a comprehensive survey

http://home.mit.bme.hu/~kollar/papers/CSaI-2003.pdf

Four-parameter fitting of sine wave testing result: iteration and convergence

This paper presents an automatic calibration system capable of calibrating measuring instruments that do not have a digital interface. Image analysis algorithms are used to automatically determine the instrument reading. It can be used with analog and with digital displays. The maximum uncertainty in the detection of the pointer's position in analog instruments is less than the human eye can discriminate.

Automatic calibration of analog and digital measuring instruments using computer vision

Low frequency impedance measurement using sine-fitting

A broadband variant of the histogram test where Gaussian noise is used as a stimulus signal is presented. A methodology allowing for an automated and extensive characterization of analog-to-digital converters (ADCs) is given. Tolerance and confidence intervals are determined both for the integral nonlinearity (INL) and differential nonlinearity (DNL) vectors, related to the number of samples acquired. Experimental results of the characterization of a VXI waveform digitizer using this methodology are shown.

Automated ADC characterisation using the histogram test stimulated by Gaussian noise

A self‐consistent, one‐dimensional, numerical solution of Schrodinger and Poisson equations has been obtained. To solve Schrodinger equation, instead of the conventional finite difference approach, we start by dividing the space in intervals of constant potential energy, in which the solution type is well known. Next we match the wave functions and their first derivatives, divided by the effective mass on each side of the potential steps. This approach is very efficient on finding the eigenvalues in structures with large regions of almost constant potential energy such as quantum well structures or heterojunctions. Validation is presented by comparing the exact solution of Schrodinger equation for a triangular well with that obtained by our method. Poisson equation is solved considering the deep (DX) and shallow centers assuming a donor with one ground state and two excited states. Applications to isotype n‐GaAs/AlxGa1−xAs graded heterojunctions show that the density of the two‐dimensional electron gas (2DEG) is almost independent of graduality when this is smaller than about 200 A and that DX centers may lower the 2DEG concentration by as much as 20%.

A. Cruz Serra

Papers

Automatic calibration of analog and digital measuring instruments using computer vision

Low frequency impedance measurement using sine-fitting

Automated ADC characterisation using the histogram test stimulated by Gaussian noise

A one-dimensional, self-consistent numerical solution of Schrödinger and poisson equations

A new four parameter sine fitting technique