Electronic Amplifiers - Science topic

Despite the progress in the development of innovative EEG acquisition systems, their use in dynamic applications is still limited by motion artifacts compromising the interpretation of the collected signals. Therefore, extensive research on the genesis of motion artifacts in EEG recordings is still needed to optimize existing technologies, shedding...

In order to implement the fifth generation (5G) communication system for a large number of users, the governments of many countries nominated the low 5G frequency band between 3.3 and 4.3 GHz. This paper proposes a wideband RFPA by designing the input matching network (MN) and output MN of the device using the simplified real frequency technique (S...

Titanium:sapphire (Ti:sapphire) lasers have been essential for advancing fundamental research and technological applications, including the development of the optical frequency comb¹, two-photon microscopy² and experimental quantum optics3,4. Ti:sapphire lasers are unmatched in bandwidth and tuning range, yet their use is restricted because of thei...

Photoacoustic imaging (PAI) utilizes the photoacoustic effect to record both vascular and functional characteristics of a biological tissue. Photoacoustic signals have typically low amplitude that cannot be read efficiently by data acquisition systems. This necessitates the use of one or more amplifiers. These amplifiers are somewhat bulky (e.g., t...

En esta investigación se presenta el diseño y construcción de una estación terrena de bajo costo, compuestas por una antena Yagi, Amplificador de bajo ruido (LNA) y un nodo receptor LoRa que permite recepción de señales de CubeSats basadas en tecnología LoRa, para lo cual se emplearon conceptos de diseño general de antenas y amplificadores electrón...

We propose an experimental method for the determination of the transfer function linewidth of a laser amplifier. This technique is based on a transfer function scan using frequency modulation to amplitude modulation (FM-to-AM) temporal modulation measurement as a function of wavelength. Using this method, we show that the output spectrum of a laser...

The coil structure of the inductive wear debris sensor plays a significant role in the effect of wear debris detection. According to the characteristics of LC parallel resonance, the capacitor and coil are connected in parallel to make sensor coils in the LC parallel resonance state, which is beneficial to improve the ability to detect wear particl...

A good approximation to power amplifier (PA) behavioral modeling requires precise baseband models to mitigate nonlinearities. Since digital predistortion (DPD) is used to provide the PA linearization, a framework is necessary to validate the modeling figures of merit support under signal conditioning and transmission restrictions. A field-programma...

Infraslow activity (ISA) is a biomarker that has recently become of interest in the characterization of seizure recordings. Recent data from a small number of studies have suggested that the epileptogenic zone may be identified by the presence of ISA. Investigation of low frequency activity in clinical seizure recordings, however, has been hampered...

Introdução: O estudo sobre a aquisição e condicionamento do sinal de eletro-oculografia, sinal de origem biológica, emitido pela diferença de potencial entre a córnea e a retina apresenta uma forte aplicação de tecnologia relacionada ao tecido biológico. O movimento do globo ocular faz com que seja gerado um sinal de baixa intensidade na casa dos m...

Corticokinematic coherence (CKC) is computed between limb kinematics and cortical activity (e.g. MEG, EEG), and it can be used to detect, quantify and localize the cortical processing of proprioceptive afference arising from the body. EEG-based studies on CKC have been limited to lab environments due to bulky, non-portable instrumentations. We rece...

Erbium-doped fiber amplifiers revolutionized long-haul optical communications and laser technology. Erbium ions could provide a basis for efficient optical amplification in photonic integrated circuits but their use remains impractical as a result of insufficient output power. We demonstrate a photonic integrated circuit–based erbium amplifier reac...

Objective: We present Myolink, a portable, modular, low-noise electrophysiology amplifier optimized for high-density surface electromyogram (HD sEMG) acquisition. Methods: Myolink consists of 4 modules. Each 108 cm module can concurrently acquire 32 unipolar electrode potentials at sampling rates of up to 8 kHz with 24-bit resolution. Modules ma...

Physical parameters of the pathogenic cells, like its volume, shape, and stiffness, are important biomarkers for diseases, chemical changes within the cell, and overall cell health. The response of pathogenic bacteria and viruses to different chemical disinfectants is studied widely. Some of the routinely employed techniques to measure these change...

An automatic non-contact cough detector designed especially for night audio recordings that can distinguish coughs from snores and other sounds is presented. Two different classifiers were implemented and tested: a Gaussian Mixture Model (GMM) and a Deep Neural Network (DNN). The detected coughs were analyzed and compared in different sleep stages...

Magnetoplethysmogram (MPG) is typically acquired by placing a giant magnetoresistance sensor (GMR)-magnet system in a blood vessel's (e.g., radial artery) vicinity. This brief analyzed multiple linearizing front ends for the GMR-magnet system. GMR based analog front end's (AFE) gain requirement is derived through COMSOL and MATLAB-based simulation...

Electrochemical impedance spectroscopy (EIS) is a useful approach for modeling the equivalent circuit of biosensors such as field-effect transistor (FET)-based biosensors. During the process of sensor development, laboratory potentiostats are mainly used to realize the EIS. However, those devices are normally not applicable for real use-cases outsi...

Medical ultrasound has become a crucial part of modern society and continues to play a vital role in the diagnosis and treatment of illnesses. Over the past decades, the develop- ment of medical ultrasound has seen extraordinary progress as a result of the tremendous research advances in microelectronics, transducer technology and signal processing...

The gyrotron travelling wave tube (gyro-TWT) is an ideal high-power, broadband vacuum electron amplifier in millimeter and sub-millimeter wave bands. It can be applied as the source of the imaging radar to improve the resolution and operating range. To satisfy the requirements of the W-band high-resolution imaging radar, the design and the experime...

Loudspeaker arrays with high directivity are desirable in many acoustic and sound applications to direct sounds into a desired region. One way of designing such arrays is through the differential operator to maximize the directivity factor. However, this method generally works for linear arrays with endfire steering direction and its usage to gener...

This paper presents a multielement annular ring ultrasound transducer formed by individual high-frequency PMUTs (17.5 MHz in air and 8.7 MHz in liquid) intended for high-precision axial focalization and high-performance ultrasound imaging. The prototype has five independent multielement rings fabricated by a monolithic process over CMOS, allowing f...

Structures, kinetics, and chemical reactivities at interfaces and surfaces are key to understanding many of the fundamental scientific problems related to chemical, material, biological, and physical systems. These steady-state and dynamical properties at interfaces and surfaces require even-order techniques with time-resolution and spectral-resolu...

This paper explores the use of the Nichols chart to study the operating regions and compute the phase margins in electronic amplifiers. Inspection of the Nichols chart allows the determination of the exact values of the phase margin at unity gain of the self-loop function in a transfer function. Hence, there is no need to use the Nyquist criterion...

Generally, two electrode based amperometric biosensors show extremely low current signal output around pico ampere (pA) to micro ampere (µA) range. This paper describes the development of electronic reader to capture and amplify four different range of current as mili, micro, nano and pico ampere and convert it to detectable voltage range as an out...

This study introduces an enhanced thermal management strategy for efficient heat dissipation from GaN power amplifiers with high power densities. The advantages of applying an advanced liquid-looped silicon-based micro-pin fin heat sink (MPFHS) as the mounting plate for GaN devices are illustrated using both experimental and 3D finite element model...

Objective: When developing approaches for automatic preprocessing of electroencephalogram (EEG) signals in non-isolated demanding environment such as intensive care unit (ICU) or even outdoor environment, one of the major concerns is varying nature of characteristics of different artifacts in time, frequency and spatial domains, which in turn caus...

In this paper, a power efficient, low-noise and high swing capacitively-coupled amplifier (CCA) for neural recording applications is proposed. The use of current splitting technique and current scaling technique in a current mirror operational transconductance amplifier (CM-OTA) has lead to a very good trade-off between power and noise. The present...

— In this article, by choosing and optimizing suitable structure in each stage, we have designed a multi-purpose low noise chopper amplifier. The proposed neural chopper amplifier with high CMRR and PSRR is suitable for EEG, LFP and AP signals while it has a low NEF. In order to minimize the noise and increase the bandwidth, a single stage current...

Amperometric electrical biosensors have small current variations at nano to micro range. There are limited number of electrical based two electrode electronic readers for biosensors are commercial available because of the amplification and noise issues at nano to micro ampere current range. The electronic reader focused on design a voltage amplifie...

Objective: The influence of the skin-electrode-amplifier interface and the input impedance of ECG recording amplifiers on transient response performance is investigated using accurate modeling of surface contact electrodes. The paper aims to establish the input impedance requirements of ECG recording amplifiers based on the electrical properties o...

This paper presents an integrated biopotential preamplifier architecture targeting applications that simultaneously require high common-mode rejection ratio (CMRR), low noise, high input common-mode range (ICMR), and current-efficiency (low Noise Efficiency Factor or NEF). A biopotential preamplifier, which performs well in line with the state-of-t...

This paper summarizes our recent progress towards Gastric Seed which is an ultrasonically interrogated millimeter-sized implant for gastric electrical activity (also known as slow waves, SWs) recording. We present a proof-of-concept wireless system designed to collect, transmit, and store in vivo SW signals by integrating a prototype Gastric Seed c...

The measurement of the electron energy distribution (EED) of electrons escaping axially from a minimum-B electron cyclotron resonance ion source (ECRIS) is reported. The experimental data were recorded with a room-temperature 14 GHz ECRIS at the JYFL accelerator laboratory. The electrons escaping through the extraction mirror of the ion source were...

The measurement of the electron energy distribution (EED) of electrons escaping axially from a minimum-B electron cyclotron resonance ion source (ECRIS) is reported. The experimental data were recorded with a room-temperature 14 GHz ECRIS at the JYFL accelerator laboratory. The electrons escaping through the extraction mirror of the ion source were...

Since the first demonstration, the electrolyte-gated organic field-effect transistors (EGOFETs) have immediately gained much attention for the development of cutting-edge technology and they are expected to have a strong impact in the field of (bio-)sensors. However EGOFETs directly expose their active material towards the aqueous media, hence a li...

A medley of flavours - Volume 130 Issue 8 - Musheer Hussain, Edward Fisher, Robin Youngs, Jonathan Fishman

The use of car windows as a long range acoustic sensing device for external alarm signals is described in this paper. The goal is to detect and localize siren signals (e.g. ambulances and police cars) and to alert presbycusic drivers of its presence by visual and acoustic feedback in order to improve individual mobility and increase the sense of se...

Electrocorticography (ECoG) is an important area of research for Brain-Computer Interface (BCI) development. ECoG, along with some other biopotentials, has spectral characteristics that can be exploited for more optimal front-end performance than is achievable with conventional techniques. This paper optimizes noise performance of such a system and...

In his splendid article "Can a biologist fix a radio? - or, what I learned while studying apoptosis," Y. Lazebnik argues that when one uses the right tools, similarity between a biological system, like a signal transduction pathway, and an engineered system, like a radio, may not seem so superficial. Here I advance this idea by focusing on the noti...

Energy harvesting from ambient environment vibration is a potential method to supply the low-power consumption devices. This paper demonstrates a new method to proceed energy harvesting using a piezoceramic. Both the mechanical and electrical excitations (hybrid stimulation) have been exerted on a piezoceramic. Current was measured though a current...

We developed an EEG- and audio-based sleep sensing and enhancing system, called iSleep (interactive Sleep enhancement apparatus). The system adopts a closed-loop approach which optimizes the audio recording selection based on user's sleep status detected through our online EEG computing algorithm. The iSleep prototype comprises two major parts: 1)...

In this paper, the wireless data and power transfer for a novel optogenetic visual cortex implant system was demonstrated by using pork tissue mimic in-vitro at the ISM 2.4 GHz and 13.5 MHz frequency band respectively. The observed data rate was 120 kbps with no loss in data for up to a thickness of 35 mm in both water & pork. To increase the power...

In the field of Brain Machine Interfaces (BMI) researchers still are not able to produce clinically viable solutions that meet the requirements of long-term operation without the use of wires or batteries. Another problem is neural compatibility with the electrode probes. One of the possible ways of approaching these problems is the use of semicond...

Electron-optical devices with microchannel amplification have many advantages, except poor noise characteristics. In order to increase gain and reduce a noise factor a layer with increased secondary emission is deposited on the top of a contact conducting layer at the entrance of channels. Effects, arising in the channel amplifier with the high-eff...

We present a system-on-a-chip (SoC) for use in high-frequency capacitive micromachined ultrasonic transducer (CMUT) imaging systems. This SoC consists of trans-impedance amplifiers (TIA), delay locked loop (DLL) based clock multiplier, quadrature sampler, and pulse width modulator (PWM). The SoC down converts RF echo signal to baseband by quadratur...

We report N-polar GaN-based tunneling hot electron amplifier transistors (THETA) with common-emitter modulation, ac current gain up to 1.35 operating at collector current density ~50 kA/cm2, which are highest values reported to date in GaN-based hot electron transistors. Achieving higher frequency operation in the III-nitride system requires an alt...

Navigating the tortuous ureter is challenging and could lead to perforation. Previously described techniques involve different types of guidewire and ureteric catheters.1 When routine techniques fail, we suggest using a 5Fr curved-tip multipurpose catheter (Tempo™ 5; Cordis, Bridgewater, NJ, US; £12.08). The curved tip combined with the ability to...

Microchannel electron multipliers, which amplify the input current of electrons through complicated stochastic processes, have found wide applications in different areas of science and engineering due to a number of remarkable properties. However, the loss of information caused by the statistical fluctuations in the gain of the channels, increases...

An algorithm for automatic synthesis of one stage analog amplifiers based on Grammatical Evolution (GE) and Koza's developmental expressions is presented. GE is an evolutionary algorithm which can generate code in any programming language and uses variable length binary strings. The binary genome determines which production rules in a BNF grammar d...

Experiment analysis on in-vivo data sequences suggests a wide system dynamic range (DR) is required to simultaneously record local field potentials (LFPs), extra-cellular spikes, and artifacts/interferences. In this paper, we present a 13 µW 87 dB DR ΔΣ modulator for full-spectrum neural recording. To achieve a wide DR and low power consumption, a...

This paper describes the design, development, and tests of a low cost ALS. It was designed for hearing-impaired student classrooms. It utilised digital wireless technology and was aimed to be an alternative to a popular FM ALS. Key specifications include transmitting in 2.4 GHz ISM band with eight selectable transmission channels, battery operated...

In this paper, a PVDF film sensor was used to measure the transient responses of a cantilever beam subjected to an impact loading. The measurement capability of a PVDF sensor is affected by the area of the PVDF film sensor and the signal conditioner (charge amplifier). The influences of these effects on the experimental measurements were investigat...

Low-power wearable recording of biopotentials requires acquisition front-ends with high common-mode rejection for interference suppression and adjustable gain to provide an optimum signal range to a cascading analogue-to-digital stage. A microcontroller operated double-differential (DD) recording setup and automatic gain control circuit (AGC) are d...

Nanopore sensors have attracted considerable interest for high-throughput sensing of individual nucleic acids and proteins without the need for chemical labels or complex optics. A prevailing problem in nanopore applications is that the transport kinetics of single biomolecules are often faster than the measurement time resolution. Methods to slow...

In the last few years our group have focused on developing various designs of spark-protected micropattern gaseous detectors featuring resistive electrodes instead of the traditional metallic ones: resistive microstrip counters, resistive GEM, resistive MICROMEGAS. These detectors combine in one design the best features of RPCs (spark-protection) a...

This paper describes the development of a cognitive prosthesis designed to restore the ability to form new long-term memories typically lost after damage to the hippocampus. The animal model used is delayed nonmatch-to-sample (DNMS) behavior in the rat, and the "core" of the prosthesis is a biomimetic multi-input/multi-output (MIMO) nonlinear model...

We present an alternative post-processing on a CMOS chip to release a planar microelectrode array (pMEA) integrated with its signal readout circuit, which can be used for monitoring the neuronal activity of vestibular ganglion neurons in newborn Wistar strain rats. This chip is fabricated through a 0.6 μm CMOS standard process and it has 12 pMEA th...

An acoustic electronic scanning array for acquiring images from a person using a biometric application is developed. Based on pulse-echo techniques, multifrequency acoustic images are obtained for a set of positions of a person (front, front with arms outstretched, back and side). Two Uniform Linear Arrays (ULA) with 15 λ/2-equispaced sensors have...

As opposed to visual imaging, biosonar imaging of spatial object properties represents a challenge for the auditory system because its sensory epithelium is not arranged along space axes. For echolocating bats, object width is encoded by the amplitude of its echo (echo intensity) but also by the naturally covarying spread of angles of incidence fro...