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Abstract This paper presents a novel switched capacitor biquad with a high gain differential amplifier for the first time using amorphous indium‐gallium‐zinc‐oxide thin‐film transistors on flexible (polyimide) substrate. The proposed low‐pass filter was successfully characterised under normal ambient conditions. The circuit has shown a 3‐dB cutoff frequency of 155 Hz and power consumption of 336 μW from measurements with a power supply voltage of 10 V. This circuit would find potential applications in wearable continuous health monitoring systems.

A polarization-maintaining buffered Fourier domain mode-locked (FDML) swept source with a center wavelength of 1300 nm is demonstrated. The scanning rate of the buffered FDML swept source is doubled without sacrificing the output power of the swept source by combining two orthogonally polarized outputs with a polarization beam combiner. The stability of the swept source is improved because the polarization state of the laser beam inside the laser cavity is maintained without the use of any polarization controllers. The swept source is capable of an edge-to-edge tuning range of more than 150 nm and a FWHM range of 95 nm at a 102 kHz sweeping rate and with an average power of 12 mW. A swept source optical coherence tomography (SSOCT) system is developed utilizing this buffered FDML swept source. The axial resolution of the SSOCT system is measured to be 9.4 µm in air. The sensitivity of the SSOCT system is 107.5 dB at a depth of 0.25 mm with a 6 dB roll-off at a depth of 2.25 mm.

The micro-displacement amplifier has been widely used to magnify the outputs of piezoelectric actuators for some large displacement required applications, and the amplification and frequency are the most important elements for designing the amplifying mechanisms. This study presents the design of a diamond-type micro-displacement amplifier (DMDA) and simulates its working performances by using the finite element method. After the theoretical values of amplification and natural frequency are calculated, the effects of system parameters such as angle, arm and body thicknesses, corner radius, side and edge widths, on the changes of amplification and stability are studied. Then experiments are carried out to verify the theoretical simulations and further study the amplification mechanism. Finally, a micro-droplet jetting dispenser featuring the DMDA is constructed. The perfect jetting performance shows the good application of DMDA in microelectronics packaging field. This study finds that with the increase of the angle and the arm thickness, the amplification decreases and the natural frequency increases obviously. A larger value of corner radius or side width produces a smaller natural frequency. Besides, the increase of edge width enlarges the amplification and reduces the natural frequency. This study can be used to guide the design of this kind of micro-displacement amplifier.

Low-voltage p-type organic transistors with two types of multi-finger source/drain contacts were fabricated on glass and polyethylene naphthalate. They exhibited threshold voltage between -0.3 and -0.5V and field-effect mobility between 0.2 and 0.4 cm2/V·s. Their transconductance in saturation operation varied from ~25 to ~60 μS and scaled with the gate dielectric capacitance and transistor dimensions. All transistors operated beyond 1 kHz, while the transistors with the shortest channel length (L = 20 μm and W = 4.03 mm) exhibited a cutoff frequency of 13.4 kHz. The transistors were used to build simple voltage amplifiers by adding a resistor Rd on the drain side of the transistor. Higher Rd required higher supply voltage Vdd but resulted in the increased voltage gain. A voltage gain in excess of 8 V/V was obtained for Vdd of -12 V and Rd of 220 kΩ when transistor with medium value of transconductance of 37 μS was used. Consequently, the voltage gain of 10 V/V is achievable, making such transistor structures viable for sensor development.

This brief presents a switchless bidirectional amplifier (BDA) with 7-to-30 GHz of bandwidth (BW) and 11.2 dB of peak gain. Common impedance matching networks (IMN) are utilized for both directions, to form a low power and compact amplification stage. It achieves +0.58 dB/BW of a gain slope, which reaches its peak value at 21 GHz. Its output-referred 1-dB compression point (OP1dB) and group delay (GD) are measured as −2.5 dBm and 41 psec. while having ± 1.5 dB and ± 9.1 psec. variation over the defined BW. Moreover, the BDA dissipates 14 mW of power in 0.42 mm2 of area (including pads). The measurement results demonstrate that the BDA is compatible with the wideband transceiver systems. To the best of the authors’ knowledge, the presented design has the best operating bandwidth with a positively sloped gain without sacrificing from the area, power consumption and other remaining RF features such as noise figure (NF). [ABSTRACT FROM AUTHOR]

The phase-sensitive detection (PSD), popularly referred to as lock-in amplifier (LIA) has been around for quite a long time. Lock-in amplifier has been quite a versatile measurement instrument for extracting low-level signals buried in noise. In the recent past, the importance of LIA has been realized as a sensor interfacing platform and a number of portable implementations targeting sensing applications have been reported. This review surveys LIA design, implementation and application as portable sensor interfaces. The paper put forward a brief history of phase-sensitive detection leading up to the state-of-the-art implementation in various fields of application. Different designs and implementation techniques for LIA have been categorized and introduced as per the design topologies. The main category being analog, digital, FPGA and CMOS integrated design. Finally, the application of LIA in resistive, capacitive, impedance, optical and Nano-bio sensors is categorized and investigated in detail. [ABSTRACT FROM AUTHOR]

• Amplifiers selectively stabilize CFTR mRNA through a co-translational mechanism. • CFTR membrane targeting efficiency is important for amplifier responsiveness. • Amplifiers selectively increase CFTR mRNA translation. • Amplifier directly binds PCBP1 with increased affinity for RNA-bound PCBP1. • PCBP1 binds a CFTR consensus site that is necessary for response to amplifier. Cystic fibrosis (CF) is a recessive disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We previously described a first-in-class CFTR modulator that functions as an amplifier to selectively increase CFTR expression and function. The amplifier mechanism is distinct from and complementary to corrector and potentiator classes of CFTR modulators. Here we characterize the mechanism by which amplifiers increase CFTR mRNA, protein, and activity. Biochemical studies elucidated the action of amplifiers on CFTR mRNA abundance and translation and defined the role of an amplifier-binding protein that was identified using chemical proteomics. Amplifiers stabilize CFTR mRNA through a process that requires only the translated sequence of CFTR and involves translational elongation. Amplifiers enrich ER-associated CFTR mRNA and increase its translational efficiency through increasing the fraction of CFTR mRNA associated with polysomes. Pulldowns identified the poly(rC)-binding protein 1 (PCBP1) as directly binding to amplifier. A PCBP1 consensus element was identified within the CFTR open reading frame that binds PCBP1. This sequence proved necessary for amplifier responsiveness. Small molecule amplifiers co-translationally increase CFTR mRNA stability. They enhance translation through addressing the inherently inefficient membrane targeting of CFTR mRNA. Amplifiers bind directly to PCBP1, show enhanced affinity in the presence of bound RNA, and require a PCBP1 consensus element within CFTR mRNA to elicit translational effects. These modulators represent a promising new and mechanistically novel class of CFTR therapeutic. They may be useful as a monotherapy or in combination with other CFTR modulators. [ABSTRACT FROM AUTHOR]

The pigmentation patterns of many carnivorous mammals comprise contrasting white patches of hair in different parts of the body whose evolution remains largely misunderstood. Some felids (Felidae) exhibit conspicuous white spots on the posterior part of the ears, while the ear color of others is uniform. On the basis that ear movement in felids has a role in intraspecific communication and that color contrast enhances detection, here it is hypothesized that white spots on ears may be particularly adaptive under conditions of poor visibility and thus be associated with the occupancy of closed habitats. This prediction was tested using phylogenetic logistic regression models with all species of extant felids. Results show a clear association between the occurrence of white spots on ears and preference for closed habitats, and this is independent of body size and whether species that occupy both closed and open habitats are considered as closed- or open-habitat specialists. Phylogenetic signal analyses indicate that the occurrence of white spots on ears is a highly conserved trait while habitat preferences are evolutionarily labile, suggesting that the presence of white spots may have partly contributed to the adaptation of felids to closed habitats. These findings indicate that some subtle pigment traits have fulfilled a significant role in determining the success of habitat occupancy by felids and possibly other mammals, which in turn has driven the evolutionary maintenance of such traits. [ABSTRACT FROM AUTHOR]

This study proposes a buck converter IC with voltage‐mode pulse‐width modulation (PWM) controller to provide a stable bias voltage for the brushless DC motor drive. The proposed buck converter IC comprises an error amplifier, a hysteresis comparator, a linear ramp generator, a driving circuit, a non‐overlapping circuit, a bootstrap circuit and a level shifter. By integrating these proposed circuits into a single chip, the performance of buck converter chip could be improved significantly. The PWM controlled signal was used to generate a suitable output voltage by modifying the duty cycle. The advantage of this method is that the control method of the feedback circuit can be implemented easily, has a short ON time, and has effective noise immunity. After verifying the designed functions, the proposed IC was fabricated using TSMC 0.25 μm 1P3M complementary metal oxide semi‐mixed signal process. Measurement results illustrate that the output voltage, output current, line regulation, load regulation, output ripple voltage and peak power efficiency were 5 V, 200 mA, 13.33 mV/V, 18.5 mV/A, 30 mV, and 68%, respectively, at an input voltage of 15 V and a switching frequency of 100 kHz. The chip area was ∼1.480 × 0.999 mm2. [ABSTRACT FROM AUTHOR]

Performance of a memory depends on the storage stability, yield and sensing speed. Differential input and the latching time of sense amplifiers are considered as primary performance factors in static random access memory. In a content addressable memory (CAM), the sensing is carried out through the matchline (ML) and the time for evaluation is the key to decide the search speed. The density of CAM is on a rise to accommodate a higher amount of information which increases the power dissipation associated with it. Issues such as the logical threshold variation and lower noise margin between match and mismatch are critical in the operation of a CAM. A good ML sensing technique can reduce the ML power with enhanced evaluation speed. This work provides an analogy of various ML sensing techniques based on their pre‐charging, evaluation and performance improvement strategies. Estimation on the power dissipation and evaluation time are made and in‐depth analysis on their power‐speed‐overhead trade‐off are carried on 64‐bit CAM macros. [ABSTRACT FROM AUTHOR]

The micro-displacement amplifier has been widely used to magnify the outputs of piezoelectric actuators for some large displacement required applications, and the amplification and frequency are the most important elements for designing the amplifying mechanisms. This study presents the design of a diamond-type micro-displacement amplifier (DMDA) and simulates its working performances by using the finite element method. After the theoretical values of amplification and natural frequency are calculated, the effects of system parameters such as angle, arm and body thicknesses, corner radius, side and edge widths, on the changes of amplification and stability are studied. Then experiments are carried out to verify the theoretical simulations and further study the amplification mechanism. Finally, a micro-droplet jetting dispenser featuring the DMDA is constructed. The perfect jetting performance shows the good application of DMDA in microelectronics packaging field. This study finds that with the increase of the angle and the arm thickness, the amplification decreases and the natural frequency increases obviously. A larger value of corner radius or side width produces a smaller natural frequency. Besides, the increase of edge width enlarges the amplification and reduces the natural frequency. This study can be used to guide the design of this kind of micro-displacement amplifier. [ABSTRACT FROM AUTHOR]

This paper presents a 4-bit, 2–2 multi-stage noise shaping (MASH) delta-sigma modulator (DSM) fabricated using a 0.18 µm complementary metal oxide semiconductor (CMOS) process. The DSM was designed using a cascade-of-integrators with a feedforward (CIFF) structure. The first integrator was designed to reduce the loading effect of the system's front-end circuit using a switched-resistor integrator instead of the conventional switched-capacitor method. The CIFF structure requires an active adder, which is generally implemented with a high-bandwidth high-swing amplifier. In this paper, the active adder is eliminated and an adder-less integrator is implemented in the MASH DSM. The DSM prototype has an over-sampling ratio (OSR) of 16 and a 160 MHz sampling frequency. The prototype's measured signal-to-noise ratio (SNR) is 82.4 dB and the signal-to-noise-plus-distortion ratio (SNDR) is 78.1 dB for a signal bandwidth of 5 MHz. The measured total power consumption is 26 mW at a 1.8 V supply voltage, and the chip core size is 0.67 mm2. The energy required per conversion step is 0.4 pJ/conv. [ABSTRACT FROM AUTHOR]

A bandwidth and slew rate (SR) enhanced operational transconductance amplifier (OTA) with proposed sustainable dynamic bias, transient detector and passive on-chip high-pass filter is presented in this brief. The proposed design is able to detect large-signal applied to the input of the amplifier and dynamically adjust its bias current to enhance both unity-gain bandwidth (UGB) and SR at the same time to achieve fast-settling behavior without overshoot and undershoot, along with high immunity against variations of supply voltage and bias current. Fabricated with a commercial 130-nm CMOS technology, the proposed design is verified by measurements that it is able to increase its SR by over 15 times, with more than 7.5 times reduction in its power consumption to attain fast settling time compared with a conventional design. Design considerations and an architectural comparison of the proposed design with another design with a different approach are also included in this brief to verify its performance and viability. [ABSTRACT FROM AUTHOR]

In this brief, we analyze two actively compensated amplifiers identified in a recently proposed negative impedance converter (NIC) regarding their phase and gain errors. We also study the use of this NIC in active compensation of a inverting amplifier and compare its performance with previously described actively compensated amplifiers. Further new NIC realizations using other actively compensated non-inverting amplifiers and their application to realize inverting amplifiers is also investigated. [ABSTRACT FROM AUTHOR]

This paper presents a new family of innovative operational transconductance amplifier (OTA) topologies based on CMOS inverter structures, with improved gain and energy-efficiency. This new family of OTA designs is suitable for biomedical and healthcare circuits and systems, due to the high energy-efficiency, improved gain and low level of noise contribution, when compared to the state-of-the-art in this field. In this paper, two fully-differential implementations are presented, a first one with a double CMOS branch biased by two pairs of voltage-combiners structures in both NMOS and PMOS configurations, and a second one with folded voltage-combiners specifically targeting low voltage applications, e.g., supplies below 1 V. The usage of voltage-combiners to bias the OTAs improves the gain and the gain-bandwidth product, therefore improving the energy-efficiency figure-of-merit. High values of figure-of-merit are achieved in both implementations, i.e., more than 1600 MHz × pF/mA and 2000 MHz × pF/mA, gain values above 53 dB and 50 dB under supply sources of 2 V and 0.7 V respectively. The folded voltage-combiners biased OTA is able to operate correctly under a voltage supply down to 0.7 V with proper DC biasing. The results are finally compared with state-of-the-art in this field and the potential of the circuits is fulfilled using a state-of-the-art layout-aware integrated-circuit optimization framework, AIDA, particularly relevant in order to overcome the device stacking problematic for lower voltages. [ABSTRACT FROM AUTHOR]

We investigated the X-ray [40 keV, 700 Gy(SiO2), ~80 mGy/s] radiation effects on the performances (gain) of Er-doped fiber preamplifier (EDFA) and Er/Yb codoped fiber boost amplifier (EYDFA). Various EDFA and EYDFA architectures have been designed to operate either in wavelength division multiplexing (WDM) or dense WDM (DWDM) schemes. We compare the performances of amplifiers based on conventional or radiation-hardened (RH) versions of the active Er-doped or Er/Yb-codoped fibers. Our results show that for all amplifier architectures, the various channels undergo similar gain degradation levels and kinetics, as expected from the measured spectral dependence of the radiation-induced attenuation of the phosphosilicate (ErYb-doped) and aluminosilicate (Er-doped) glass matrixes of these fibers. This degradation remains very limited for the amplifiers based on RH fibers, with a gain decrease of less than 0.3 mdB.Gy−1 for the EDFA (~30 dB initial gain) and less than 0.8 mdB.Gy−1 for the EYDFA (~18 dB initial gain) in the DWDM architecture. [ABSTRACT FROM AUTHOR]

• Standard instrumentation ensures high quality recordings and enables comparison of results. • This consensus document on "Standards of Instrumentation of EMG" is written by an expert panel. • This report covers technical aspects as well as topics for optimal and standardized examinations. Standardization of Electromyography (EMG) instrumentation is of particular importance to ensure high quality recordings. This consensus report on "Standards of Instrumentation of EMG" is an update and extension of the earlier IFCN Guidelines published in 1999. First, a panel of experts in different fields from different geographical distributions was invited to submit a section on their particular interest and expertise. Then, the merged document was circulated for comments and edits until a consensus emerged. The first sections in this document cover technical aspects such as instrumentation, EMG hardware and software including amplifiers and filters, digital signal analysis and instrumentation settings. Other sections cover the topics such as temporary storage, trigger and delay line, averaging, electrode types, stimulation techniques for optimal and standardised EMG examinations, and the artefacts electromyographers may face and safety rules they should follow. Finally, storage of data and databases, report generators and external communication are summarized. [ABSTRACT FROM AUTHOR]

A modified recycling folded cascode (MRFC) operational transconductance amplifier (OTA) for achieving high DC gain, slew rate, and unity gain bandwidth (UGB) is proposed in this paper. Positive feedback is adopted to enhance DC gain and unity gain bandwidth. The proposed MRFC OTA is compared with conventional folded cascode (FC), recycling folded cascode (RFC), and other OTAs existing in the literature. Three OTAs, FC, RFC, and MRFC, are realized and implemented using the UMC 180 nm CMOS process for the same bias current of 300 μA. The designs are simulated in the Cadence Spectre Environment. From the simulation results, it may be noted that the proposed amplifier achieves a gain of 76.24 dB and unity gain bandwidth of 74.7 MHz with an input referred noise and slew rate of 139.2 μVrms and 64.05 V/μs respectively. The proposed amplifier occupies an area of 2760 μm2 . [ABSTRACT FROM AUTHOR]

This brief presents an active equalizer circuit with positive gain slope at X-Band (8–12 GHz). Compared to passive examples, the active equalizer realized better filter and impedance characteristics in frequency of interest with increased functionality for a single amplification stage. It achieved close to 10 dB of peak gain, a +1.13 dB/GHz gain slope with 2.8 dB noise figure (NF) by utilizing cascode topology. The design reaches a −1.5 dBm input-referred compression point (input-P1dB) while consuming 46 mW of power. To the best of authors’ knowledge, the presented work achieves the best on-chip gain, a gain slope and NF performance in the literature as an equalizer that utilizes SiGe BiCMOS technology. [ABSTRACT FROM AUTHOR]

This paper proposed a novel structure of a 10-bit, 400MS/s pipelined analog to digital convertor using 0.18 µm TSMC technology. In this paper, two stages are used to converter design and a new method is proposed to increase the speed of the pipeline analog to digital convertor. For this purpose, the amplifier is not used at the first stage and the buffer is used for data transfer to the second stage, in the second stage an amplifier circuit with accurate gain of 8 that is open loop with a new structure was used to speed up, also the design is such that the first 4 bits are extracted simultaneously with sampling. On the other hand, in this structure, since in the first stage the information is not amplified and transferred to the second stage, the accuracy of the comparator circuit should be high, therefore a new structure is proposed to design a comparator circuit that can detect unwanted offsets and eliminate them without delay, and thus can detect the smallest differences in input voltage. The proposed analog to digital convertor was designed with a resolution of 10 bits and a speed of 400MS/s, with the total power consumption 74.3mW using power supply of 1.8v. [ABSTRACT FROM AUTHOR]

We present characteristics of a wavelength swept laser with a scanning fiber Fabry-Perot filter at 1300 nm. We investigate the dependence of the scanning frequencies in the swept laser. In conventional wavelength swept lasers, the relative intensity of the laser output decreases significantly as the scanning frequency increases. The peak wavelength of the output spectrum is red-shifted due to the nonlinear frequency downshifting in the semiconductor optical amplifier (SOA). In the Fourier domain mode-locked (FDML) wavelength swept laser, we investigate transient intensity profiles and the full width at half maximum in response to the injection currents and detuning of the scanning frequency. The degradation of the scanning range of the swept laser is caused by the deviation from the scanning frequency at 45.6 kHz. In addition, transient intensity profiles show significant asymmetric behavior in response to the detuned frequencies. Finally, the axial resolution and sensitivity as a function of imaging depth are analyzed for both forward and backward scans. With the FDML laser, the detection sensitivity up to 102 dB is achieved for the backward scans. The backward scans exhibit higher axial resolution and sensitivity than the forward scan. (C) 2008 Optical Society of America.

The paper presents the research and development of a low-volume brightness amplifier for imaging laser active optical systems (laser monitors) with a pulse repetition frequency (PRF) of up to 100 kHz. A small-sized active element and pumping source based on tasitron have been developed. The effect of the brightness amplifier's operating features (concentration of CuBr and HBr) on the numerical characteristics of images obtained in the laser monitor has been studied. The optimal concentrations were determined, and it was proven for the first time that they should be 30% lower than what is needed for obtaining maximum laser power. It was shown that increasing the CuBr concentration leads to a decrease in the field of view. The effect of the one-pass amplification profile on the quality of LOAS-based images was experimentally determined. A small-sized active element (40 cm3) excited with a specific pulse energy input of 238 μ J/cm3 can be used to obtain images with a time resolution of up to 10 μ s. • 100 kHz CuBr low volume brightness amplifier was developed. • The optimal operating mode of the active element is determined and provided by lower concentration of CuBr and HBr in active medium. • The field of view of laser monitor determined by the beam profile of brightness amplifier and can be increased by decreasing CuBr concentration. [ABSTRACT FROM AUTHOR]

Abstract An optical phase‐sensitive amplifier (PSA) has the potential of low‐noise optical amplification. A frequency non‐degenerate PSA (ND‐PSA) can amplify arbitrary modulation formats including higher‐order QAM. The ND‐PSA requires a co‐propagating phase conjugated light (idler light) that has been conventionally created with an optical phase conjugator at the transmitter side. We propose a transmitter configuration using simultaneous signal generation of both a signal and its idler by double‐sideband modulation for transmission systems with ND‐PSAs. The proposed scheme provides a simple configuration with a single Mach–Zehnder amplitude modulator without optically creating the idler light. We performed experiments using 16QAM, 32QAM, and probabilistically shaped 256QAM signals. As a result, a phase‐sensitive amplification with each modulation format was successfully demonstrated using the proposed transmitter configuration.