A power efficient and simple scheme for dynamically biasing cascode amplifiers and telescopic op-amps

A simple dynamic biasing scheme to extend the input/output range of cascode amplifiers is introduced. It requires minimum extra hardware and no additional power consumption. A dynamic biased telescopic op-amp is discussed as an application example. Experimental results of a fabricated test chip in 0.5 μm CMOS technology are presented that verify the proposed technique.     

Foldable Printed Circuit Boards on Paper Substrates

This paper describes several low‐cost methods for fabricating flexible electronic circuits on paper. The circuits comprise i) metallic wires (e.g., tin or zinc) that are deposited on the substrate by evaporation, sputtering, or airbrushing, and ii) discrete surface‐mountable electronic components that are fastened with conductive adhesive directly to the wires. These electronic circuits—like conventional printed circuit boards—can be produced with electronic components that connect on both sides of the substrate. Unlike printed circuit boards made from fiberglass, ceramics, or polyimides, however, paper can be folded and creased (repeatedly), shaped to form three‐dimensional structures, trimmed using scissors, used to wick fluids (e.g., for microfluidic applications) and disposed of by incineration. Paper‐based electronic circuits are thin and lightweight; they should be useful for applications in consumer electronics and packaging, for disposable systems for uses in the military and homeland security, for applications in medical sensing or low‐cost portable diagnostics, for paper‐based microelectromechanical systems, and for applications involving textiles.     

Micro-disks embedded microring for optical filter

We propose a novel ultra compact structure of micro-disks embedded microring filter (MDEMR) and several parameters which impact the performance of MDEMR are analyzed. The filter is shown to exhibit much smaller size and better spectrum than traditional microring one. The number and radius of the inner disks are found to mainly influence the resonance frequency of the micro-disks, and the valley of transmittivity. The resonance between microring and micro-disks is decrease with increasing the gap between microring and micro-disks, which also leads to the extinction ratio improved significantly. The Q factor is found to be improved from 300 to 3000 with the gap increased from 0.2 μm to 0.4 μm, while the transmission peak affected slightly.     

A “Two-Part” Resonance Circuit based Detachable Sweat Patch for Noninvasive Biochemical and Biophysical Sensing

Wearable electronics play important roles in noninvasive, continuous, and personalized monitoring of multiple biosignals generated by the body. To unleash their full potential for the next-generation human-centered bio-integrated electronics, wireless sensing capability is a desirable feature. However, state-of-the-art wireless sensing technologies exploit rigid and bulky electronic modules for power supply, signal generation, and data transmission. This study reports a battery-free device technology based on a “two-part” resonance circuit model with modularized, physically separated, and detachable functional units for magnetic coupling and biosensing. The resulting platform combines advantages of electronics and microfluidics with low cost, minimized form factors, and improved performance stability. Demonstration of a detachable sweat patch capable of simultaneous recording of cortisol concentration, pH value, and temperature highlights the potential of the “two-part” circuit for advanced, transformative biosensing. The resulting wireless sensors provide a new engineering solution to monitoring biosignals through intimate and seamless integration with skin surfaces.     

Chopper Modulators Using Current Conveyor Analogue Switches

The new CMOS Cowan, Ring, and Full-AM chopper modulators using current conveyor analogue switches are presented. The proposed chopper modulators use a square wave carrier current for controlling the transfer of a sine wave baseband voltage from nodes Y to nodes X, and the baseband currents from nodes X to nodes Z, of the current conveyors. The proposed chopper modulators are verified by simulating from the layout with a 0.5 μ m/level 49 MOSFET model of AMI obtained through MOSIS. With a supply voltage of ± 1.5 V, the operation range for the baseband voltage is between −300 mV and 300 mV. The operation range for the carrier current, bias currents for CCIIs, is ranged from ten to few hundred microamps. Using the carrier current of 20 μ A, the power consumption is not more than 0.8 mW in the operation range of the baseband voltage.     

驱动电路一致性对光纤陀螺用SLD光源特性的影响

针对目前同批次驱动电路对同一光源控制效果存在差异的问题,开展器件一致性对光纤陀螺用SLD光源特性影响的研究,找到影响驱动电路一致性的关键部位,并提出解决方案,从而规范驱动电路制作过程。理论分析结果表明:造成温控电路差异的因素由大到小依次是惠斯通桥两臂电阻偏差、热敏电阻与同臂电阻偏差、正/负电源精度、运算放大器输入失调电压,以及积分电路的运放精度;造成恒流源电路差异的因素主要是指示器误差、驱动电流漂移误差和恒流源器件选配误差;通过采取元器件配对、调试、更换高精度器件等措施,可消除或大幅降低上述电路差异。试验结果证明,按照理论规范生产的驱动电路板一致性显著提高,可达到同类进口驱动电路的水平。     

Investigation of MOSFET operation in bipolar mode

The work is concerned with the properties of conventional MOSFET in bipolar mode of operation. It is shown that the base current can provide useful information about interface trap density at the Si–SiO₂ interface. The new device characteristics are found promising for use in low-voltage low-power logic circuits.     

Riemannian geometry of quantum computation

A review is given of some recent developments in the differential geometry of quantum computation for which the quantum evolution is described by the special unitary unimodular group, SU(2ⁿ). Using the Lie algebra su(2ⁿ), detailed derivations are given of a useful Riemannian geometry of SU(2ⁿ), including the connection and the geodesic equation for minimal complexity quantum computations.     

A Circuit Architecture for Analog On-Chip Back Propagation Learning with Local Learning Rate Adaptation

In this paper we present the analog CMOS architecture of a Multi Layer Perceptron network with on-chip stochastic Back Propagation learning. The learning algorithm is based on a local learning rate adaptation technique which makes the on-chip implementation more efficient (i.e. fast convergence speed) with respect to similar architectures presented in the literature. Circuit simulation results on the XOR learning problem validate the network behavior.     

ESD issues in compound semiconductor high-frequency devices and circuits

The need of ESD protection for high frequency devices and circuits is underlined by reviewing the compound semiconductor material properties with emphasis on ESD stress and by collecting their ESD failure thresholds. Basic requirements for possible ESD protection structures in the microwave frequency regime are discussed and possible ESD protection devices and circuit concepts are proposed.