A 58-dBΩ 20-Gb/s inverter-based cascode transimpedance amplifier for optical communications

This work presents a high-gain broadband inverter-based cascode transimpedance amplifier fabricated in a 65-nm CMOS process. Multiple bandwidth enhancement techniques, including input bonding wire, input series on-chip inductive peaking and negative capacitance compensation, are adopted to overcome the large off-chip photodiode capacitive loading and the miller capacitance of the input device, achieving an overall bandwidth enhancement ratio of 8.5. The electrical measurement shows TIA achieves 58 dBΩ up to 12.7 GHz with a 180-fF off-chip photodetector. The optical measurement demonstrates a clear open eye of 20 Gb/s. The TIA dissipates 4 mW from a 1.2-V supply voltage.

Synthesis of 5,15-A2BC-Type Porphyrins to Modify a Field-Effect Transistor for Detection of Gram-Negative Bacteria

Current biological sensing technologies of bacteria are time consuming, labor intensive and thus expensive. Furthermore, their accuracy and reproducibility could be improved. Conventional electrical measurement methods might combine high sensitive sensing systems with biological requirements. A promising approach is the trapping of bacteria on the surface of the gate-electrode of a modified field-effect transistor (FET) using porphyin based self-assembled monolayers (SAMs). 5,15-A2BC-type porphyrins were synthesized originating from a 5,15-diphenylporphyrin with the functionality to connect to a gold surface. The SAM formation on the surface of the gold electrode was proven by well-established analytical methods. In this work a synthesis route is presented for a linker which is attached to a peptide or cysteine group for trapping of Gram-negative bacteria. Fluorescence lifetime imaging microscopy (FLIM) measurements of porphyrin-stained bacteria were performed to verify the linkage ability.

Error factors of AC-DC conversion circuits accuracy

Voltage standard source is an important basic instrument in the electrical measurement and testing field, and it has important guarantee significance for many industries. AC voltage standard source is based on AC-DC conversion technology to achieve output function of high precision AC voltage. In order to get a better effect of AC-DC conversion, the three factors—operational amplifier, resistance and diode—that have a greater impact on the accuracy of the rectifier output were taken the research object, and their impacts on the circuit error were analyzed respectively. The output result was compared with the output of full wave precision rectification circuit under ideal state, and the scheme of reducing error in the precision rectifier circuit was summarized, which provides a reference for improving the accuracy of AC-DC conversion in the design of full wave rectifier circuit.

Synthesis Methods of Polyaniline Based Composites

Polymer composites synthesized in the present work have been studied extensively. Polymer composites are investigated using sophisticated analytical tools. Electron microscopy was used to study the surface morphology by SEM/FESEM and dispersion of nanoparticles in the polymer matrix by HRTEM. The structural details, i.e., crystallite size, crystallinity, types of nano structure were studied by X-ray diffraction. H1-NMR, ESI-MS and FTIR have been used to elucidate chemical structure of synthesised monomers. The conformational variations in the polymeric materials have been studied using vibrational spectroscopy employing Fourier Transform Infrared (FTIR) spectroscopy. The UV-Visible absorption spectroscopy was used to study the optical properties of the monomers, and as-prepared polymeric samples. The DC conductivity measurement was carried out to study the electronic properties and charge transport mechanisms of the prepared polymeric samples. The gas sensing response was found by electrical measurement. Thermal study has been used to study the stability of prepared materials.

Development of Mobile Augmented Reality Based Media for An Electrical Measurement Instrument

The research aims to develop mobile learning media with augmented reality for electrical measurement instruments. The learner can use this application to improve their skills and knowledge about using electrical measurement instruments correctly. One of the essential skills for electricians is using voltmeter, ammeter, and ohmmeter. The result of measuring they can do some analysis about an issue or troubleshooting the electrical field. From the development research, was produced learning media application product was named ARAVO. ARAVO is an abbreviation of augmented reality of Ammeter, Voltmeter, and Ohmmeter. ARAVO helps learners and even lecturers to simulate the use of electrical measuring instruments by combining virtual objects such as multimeter with the real world. Thus will provide a more visible visualization of how to use electrical measuring instruments before they practice directly with actual measuring instruments. ARAVO is a mobile application that can run on the smartphone platform mobile Android. Into the development of this application must go through several stages before it is ready for use.

The Research on Anti-DC current Transformer of Dual Iron Core Structure with Air Gap

Current transformer (CT) is wildly used in electrical measurement and relay protection. In order to improve the power system stability in DC bias, the CT performance of anti-DC is necessarily to be enhanced. Based on the Jiles-Atherton theory, the magnetization characteristics of iron core with different air gap was analyzed in this paper. A simulation model was established using the Simulink toolbox, and the ratio error and angle error were investigated in different air gap length. Simulation result shows that the maximum magnetic density of iron core almost stays uncharged with the addition of air gap. Furthermore the slope of magnetization curve decreased, which leads to the increase of iron core saturation current. Current transformer with closed and air gap iron core possesses a stable measurement error in condition of severe DC bias.

Enabling comprehensive optogenetic studies of mouse hearts by simultaneous opto-electrical panoramic mapping and stimulation

During the last decade, cardiac optogenetics has turned into an essential tool for investigating cardiac function in general and for assessing functional interactions between different myocardial cell types in particular. To advance exploitation of the unique research opportunities offered by this method, we develop a panoramic opto-electrical measurement and stimulation (POEMS) system for mouse hearts. The core of the experimental platform is composed of 294 optical fibers and 64 electrodes that form a cup which embraces the entire ventricular surface of mouse hearts and enables straightforward ‘drop&go’ experimentation. The flexible assignment of fibers and electrodes to recording or stimulation tasks permits a precise tailoring of experiments to the specific requirements of individual optogenetic constructs thereby avoiding spectral congestion. Validation experiments with hearts from transgenic animals expressing the optogenetic voltage reporters ASAP1 and ArcLight-Q239 demonstrate concordance of simultaneously recorded panoramic optical and electrical activation maps. The feasibility of single fiber optical stimulation is proven with hearts expressing the optogenetic voltage actuator ReaChR. Adaptation of the POEMS system to larger hearts and incorporation of additional sensors can be achieved by redesigning the system-core accordingly.