Analog Amplifier Research Articles

Investigation of the Impact of BTI Aging Phenomenon on Analog Amplifiers

Investigation of the Impact of BTI Aging Phenomenon on Analog Amplifiers

A phased approach for the adaptation of telemedicine in arrythmia management.

Cardiovascular disease is the world's leading cause of death. People at higher risk of heart disease need early detection to prevent or delay serious disease complications. In this paper, we present a new design of a wireless portable ECG (electrocardiogram). The ECG signal was preprocessed by analog filters and amplifiers before it was converted into digital data via an Arduino board, a highly available device for real-time signal processing. In order to allow communication between Arduino and Android phone, we use a Bluetooth module. The proposed mobile telemedicine technique allows immediate and rapid detection of heart defects followed by an alarm message from the patient to the doctor.

SKKL PERFORMANCE ANALYSIS OF SUBMARINE CABLE COMMUNICATION SYSTEM (SKKL) EDFA - SOA AMPLIFIER LINK JAVA – BALI USING OPTISYSTEM

The Submarine Cable Communication System (SKKL) is a communication backbone that is deployed under the sea that used to connect networks between islands and between countries. DWDM (Dense Wavelength Division Multiplexing) technology can support long distance communication. Repeater used to reduce the impact of loss, on the detector side the signal can be detected properly. EDFA (Erbium Doped Fiber Amplifier) and Semiconductor Optical Amplifier (SOA) amplifiers can minimize the impact of loss and increasing the gain of each amplifier. The EDFA (Erbium Doped Fiber Amplifier) is an optical amplifier that can work at a wavelength of 1550 nm which provides amplification for the input signal that passes through it which is doped with the element erbium (Er). SOA amplifier is an optical amplifier that utilizes cavity or room cavity to strengthen light. By using branching unit configuration and repeaterless, repeatered, and parallel in-line amplifier configuration and optical system software 7.0 with system reliability parameters such as Q-factor, Bit Error Rate, Power Receiver, and Signal to Noise Ratio with power variations (0 dBm, 2 dBm, 4 dBm, 6 dBm, 8 dBm) at a frequency of 100 GHz for 10 channels. The best result on the Q-Factor parameter is 15,928, the BER parameter is 5.87 x 10-057, the receiver power parameter is -10,319 dBm, and the SNR is 42,713 dB. In this research the best value obtained in the Parallel in-line configuration. So as the best average is in the Repeatered EDFA configuration.

Ohmic-Contact-Gated Carbon Nanotube Transistors for High-Performance Analog Amplifiers.

The growing demand for ubiquitous data collection has driven the development of sensing technologies with local data processing. As a result, solution-processed semiconductors are widely employed due to their compatibility with low-cost additive manufacturing on a wide range of substrates. However, to fully realize their potential in sensing applications, high-performance scalable analog amplifiers must be realized. Here, ohmic-contact-gated transistors (OCGTs) based on solution-processed semiconducting single-walled carbon nanotubes are introduced to address this unmet need. This new device concept enables output current saturation in the short-channel limit without compromising output current drive. The resulting OCGTs are used in common-source amplifiers to achieve the highest width-normalized output current (≈30 µA µm-1 ) and length-scaled signal gain (≈230 µm-1 ) to date for solution-processed semiconductors. The utility of these amplifiers for emerging sensing technologies is demonstrated by the amplification of complex millivolt-scale analog biological signals including the outputs of electromyography, photoplethysmogram, and accelerometer sensors. Since the OCGT design is compatible with other solution-processed semiconducting materials, this work establishes a general route to high-performance, solution-processed analog electronics.

New Approach of Efficiency Improvement in 10 dB Doherty Power Amplifier for 4G LTE and 5G Wireless Applications

In this research article, the design procedure and comparative analysis of the 10 dB Doherty power amplifier (DPA) with single and double auxiliary amplifier for maximum efficiency has been presented. A new Doherty amplifier structure with parallel two auxiliary amplifiers based on conventional design having optimum value of load resistance of 3.162 ohm has been proposed with higher efficiency of 85.803% and analyzed with n-tone sinusoidal signal. The proposed Doherty power amplifier can achieve drain efficiency of 83.299% & with single and 85.803% with dual auxiliary amplifier at the output power back, off of 10 dB from the saturated power point. The simulated outputs are matched with mathematically derived design values. The simulated n-tone time response shows that the proposed design of DPA can able to handle different modulation standards at different frequencies with compatible structure.

Parallel hybrid linear-switched power amplifier and control strategy for machine emulation

Machine Emulation (ME) is one of the main applications of Power-Hardware-In-the-Loop (PHIL) simulations. The performance and cost of an ME system depends heavily on the type of Power Amplifier (PA) it employs. Linear Power Amplifiers (LPAs) produce ripple free outputs and offer high bandwidths but are costly. Switch-Mode Power Amplifiers (SMPAs) are more affordable, with higher power density, but produce switching harmonics that yield distorted waveforms and reduce the closed loop bandwidths. In order to get a compromise between these technologies for ME, this paper proposes an ME based on a Hybrid Power Amplifier (HPA), with parallel LPA and SMPA. A new current control scheme for the HPA, suitable for voltage-in current-out machine models, is proposed to reduce the required current rating, and thus the cost, of the LPA. A design procedure for the control scheme of the HPA is presented and illustrated for the emulation of a direct-online start-up of an Induction Machine (IM). Simulation results evaluate and compare systems built exclusively with SMPA or LPA for ME. Experimental results are shown to validate the proposed control scheme for the parallel HPA in ME systems. Besides, the impact of the bandwidths of the control loops of the LPA and SMPA and the switching frequency of the SMPA, on the accuracy of the ME system and on the current requirement of the LPA are highlighted.

Triple-sensitivity X-ray computed tomography using analog and digital amplifiers

Triple-sensitivity X-ray computed tomography using analog and digital amplifiers

Hybrid dual-gain tunable integrated InP-Si3N4 external cavity laser.

We present a hybrid dual-gain integrated external cavity laser with full C-band wavelength tunability. Two parallel reflective semiconductor optical amplifier gain channels are combined by a Y-branch in the Si3N4 photonic circuit to increase the optical gain. A Vernier ring filter is integrated in the Si3N4 photonic circuit to select a single longitudinal mode and meanwhile reduce the laser linewidth. The side-mode suppression ratio is ∼67 dB with a pump current of 75 mA. The linewidth of the unpackaged laser is 6.6 kHz under on-chip output power of 23.5 mW. The dual-gain operation of the laser gives higher output power and narrower linewidth compared to the single gain operation. It is promising for applications in optical communications and light detection and ranging systems.

Sandstorm effect on experimental optical camera communication.

Sandstorms can severely affect the reliability of outdoor optical wireless communications (OWC) by diminishing large regions' visibility. In this work, the effect of a real sandstorm on optical camera communications (OCC) links is experimentally evaluated. Two link ranges are essayed using a cost-efficient telescope-based camera setup with commercial LEDs. Using on-off keying modulation, a data rate of 1035 and 630 bps with error probabilities of 9.14⋅10-5 and 4.1⋅10-3 for 100 m and 200 m, respectively, can be achieved. The signal-to-noise ratio of the links was optimized by tuning the analog amplifier's gain of the camera, increasing it by up to 9 dB. It is shown that scattering due to the sandstorm can even be beneficial for increasing the data rate in OCC (contrary to classical photodetector-based OWC links), thanks to an increment of 33% on the region of interest dimensions compared to the expected clear air link.

Wide application feasibility report on graphene

In 2005, Dennard scaling, which had hitherto delivered the performance enhancement of integrated circuit (IC) chips, completely collapsed. Hence, the need for new materials and material research emerged. Two-dimensional (2D) graphene emerged as a device material, and two-dimensional hexagonal boron nitride (BN) has emerged as the ideal substrate material. For the ongoing digital revolution to be sustained, petabit/second and exabit/second transmission links are needed. Graphene technology has matured to the level where functional graphene ICs on the wafer scale can be implemented, such as frequency multipliers, high-frequency graphene analog amplifiers and quaternary digital modulation circuits. These functional graphene ICs can be fabricated at the wafer scale because of the development of the imperfection-immune paradigm called very-large-scale-integration-compatible metallic carbon (C) nanotube removal technique. To harness the exotic properties of graphene nanomaterials in real-life applications at the macro scale, three-dimensional graphene-based monoliths have been developed, which could become the basis of future batteries and solar cells. Terahertz graphene chips will herald peta- and exabit rate optical fiber communication, which is the answer to the large data workload of the Internet. Graphene is emerging as an important thermoelectric material that is capable of converting temperature difference into electric current.

A High Gain Low-Noise Amplifier Based on ITO-Stabilized ZnO Thin-Film Transistors

A novel high gain low-noise analog amplifier based on n-type indium tin oxide (ITO)-stabilized ZnO thin-film transistors (TFTs) was studied in this work. Amplifiers with capacitor bootstrap structure are proposed. The effect of unequal numbers of bootstrap structure, various capacitance, and different circuit topology on the gain and noise of circuits were investigated. The input referred noise of five kinds of amplifier circuits, Amp1, Amp2 (C444, C333, C422), and Amp3 were measured to be 101.1, 44, 47.3, 43.5, and $38.3~\mu \text{V}_{rms}$ , respectively, and the gains are 19.5, 28.8, 26.8, 25.7, and 32 dB, respectively. It is found that as the numbers of bootstrap structure increase in a small range, the input referred noise decreases, and the circuit gain increases. The effects of the capacitance on the gain or noise can be negligible. And also, the gain of the circuit with cascode structure is higher than that with common source. Results show that the noise is much lower than that of a-InGaZnO (IGZO) TFTs technology, which is widely used in TFT circuits design. The proposed high gain and low-noise analog amplifier with the ITO-stabilized ZnO TFTs technology has great potential in the biomedical fields like electro cardiogram (ECG) and pulse detection, as well as wearable electronic applications.

Phase Current Sensing Method Using Three Shunt Resistors to Eliminate Immeasurable Area in Voltage Vector Plane

This paper proposes a current sensing method to eliminate the immeasurable areas in three-phase inverters using the shunt resistors. Conventional shunt resistor-based current sensing methods have immeasurable areas in the voltage vector plane. Since motor control performance is degraded by the immeasurable area, various current reconstruction techniques have been proposed to expand the measurement range. Nevertheless, the software algorithm is quite complex, and the reconstruction ability is still unsatisfactory. In the proposed method, shunt resistors are located in series with the inverter output lines to obtain the motor phase currents. Both ends of the shunt resistors are at the high-potential as the dc-link voltage. High-potential voltages are lowered to the common-mode voltage level of the analog amplifier using voltage divider, and voltage drops across shunt resistors are detected by instrumentation amplifiers. Immeasurable areas are completely eliminated because phase currents can be detected directly through line shunt resistors. Simulations and experiments are carried out to verify the effectiveness of the proposed current sensing method.

Directional magnetic Barkhausen noise measurement using the magnetic needle probe method

A directional local magnetic measurement technique as example of measuring the angular dependence of the magnetic Barkhausen noise in electrical and construction steels at typical quasi-static frequency by the magnetic needle probe (MNP) method is presented. The directional measurement configuration of the MNP method is typical of a half-turn search coil sensor coupled to high gain analogue amplification and high order filtration stages, owing to its very weak induced electromotive force. The method exploits the MBNenergy(H) hysteresis cycle (time integration of the square of the MBN voltage signal as a function of the tangent excitation field H) and brings forth stable indicators possibly related to the Magnetocrystalline Anisotropy Energy (MAE). Experimental tests performed on grain-oriented Fe-Si and low carbon steel specimens, and comparison with the conventional search coil measurement results were worth the validation of the MNP method. These results put to the front the good directional selectivity of the MNP method over the conventional MBN sensors adversely affected by the transverse fields at the material surface. Eventually, the printed magnetic needle probe (PMNP) sensor was relatedly described to provide non-invasive directional measurements for continuous structural health monitoring.

Attenuation characteristics of an extended-wear hearing aid: Impulse and continuous noise.

The extended-wear hearing aid (EWHA) is a hearing assistive device that combines a low-power analog amplification circuit with a soft biocompatible foam plug that allows it to remain in the ear canal for several months at a time without replacement. EWHAs fit snugly in the ear canal and are not vented and so produce insertion losses comparable to a passive earplug when inserted into the ear canal with the active circuitry turned off. However, EWHAs are not marketed as hearing protection devices, and other than a general warning to users that the device will have impaired auditory awareness when the device is inserted in the "off" mode, relatively little has been reported about the attenuation characteristics of EWHAs. In this study, commercially-available EWHAs were evaluated using the ANSI standard procedures for measuring hearing protector attenuation in impulse noise [ANSI (2010). S1242-2010, Methods for the Measurement of Insertion Loss of Hearing Protective Devices in Continuous or Impulsive Noise Using Microphone-In-Real-Ear or Acoustic Text Fixture Procedures (American National Standards Institute, New York)] and in continuous noise [ANSI (2006). S12.6, Methods for Measuring the Real-Ear Attenuation of Hearing Protectors (American National Standards Institute, New York)]. Attenuation values were also measured in double and triple protection conditions that combined EWHAs with traditional earplugs and earmuffs. The results show that properly-fit EWHAs can provide passive attenuation comparable to conventional passive earplugs, which may make it possible to use them to provide persistent protection from intermittent noise sources.

An efficient method to compute simplified noise parameters of analog amplifiers using symbolic and evolutionary approach

AbstractSymbolic circuit analysis suffers as the symbolic terms increases by many folds with the increase in the size of the circuit. Hence simplification techniques are used for the analysis of the circuits which are larger in size. In this work, multi‐objective evolutionary optimisation algorithms for obtaining simplified symbolic expressions of analog amplifier circuits are presented which are not only very efficient in terms of speed and the amount of circuit reduction but also solve the accuracy problems. Initially, all MOSFETs are replaced with their nullor equivalent model. Then, the formulation of accurate fully‐symbolic noise expressions is carried out by the application of symbolic nodal analysis. The derived exact symbolic expressions are then simplified using an evolutionary approach. This method has been successfully coded in MATLAB. The numerical results obtained before and after simplification are compared with SPICE simulation to demonstrate the efficiency of the proposed methodology.

Reconfigurable structured light generation in a multicore fibre amplifier

Structured light, with spatially varying phase or polarization distributions, has given rise to many novel applications in fields ranging from optical communication to laser-based material processing. However the efficient and flexible generation of such beams from a compact laser source at practical output powers still remains a great challenge. Here we describe an approach capable of addressing this need based on the coherent combination of multiple tailored Gaussian beams emitted from a multicore fibre (MCF) amplifier. We report a proof-of-concept structured light generation experiment, using a cladding-pumped 7-core MCF amplifier as an integrated parallel amplifier array and a spatial light modulator (SLM) to actively control the amplitude, polarization and phase of the signal light input to each fibre core. We report the successful generation of various structured light beams including high-order linearly polarized spatial fibre modes, cylindrical vector (CV) beams and helical phase front optical vortex (OV) beams.

Optimal Sizing of Recycling Folded Cascode Amplifier for Low Frequency Applications Using New Hybrid Swarm Intelligence-Based Technique

ABSTRACT A new efficient design approach for sizing a high performance analog amplifier circuit namely the Recycling Folded Cascode (RFC) amplifier is presented. A RFC amplifier is an enhanced version of the conventional folded cascode amplifier and achieves better slew rate, gain, bandwidth, offset etc. for same area and power budget. Low frequency amplifiers such as biomedical or neural have a demanding requirement of low area, low power and low noise apart from meeting other optimal design specifications which have inherent trade-off amongst themselves. As a result, manual sizing becomes a computationally inefficient approach. Thus, swarm based optimization techniques have been employed to efficiently determine the optimal sizing for the RFC amplifier such that the area is minimized while meeting all the optimal design specifications considering the constraints. A new hybrid whale particle swarm optimization (HWPSO) algorithm is employed which takes advantage of the good qualities of both the whale algorithm and the PSO algorithm to optimize the area with less computational complexity. Simulations and statistical analysis have been performed and comparisons with other state of art algorithms reveals that HWPSO-based approach achieves a minimum circuit area of 21 µm2 with a mean Friedman’s statistical rank of 2.05 while meeting optimal design specifications for low frequency systems. Finally, validation with circuit design tool Cadence Virtuoso is done and pre as well as post layout analysis have been performed which further illustrated a close agreement with algorithmic results.

Analogue two-dimensional semiconductor electronics

Digital electronics are ubiquitous in the modern world, but analogue electronics also play a crucial role in many devices and applications. Analogue circuits are typically manufactured using silicon as the active material. However, the desire for improved performance, new devices and flexible integration has—as for their digital counterparts—led to research into alternative materials, including the use of two-dimensional (2D) materials. Here, we show that operational amplifiers—a basic building block of analogue electronics—can be created using the 2D semiconductor molybdenum disulfide (MoS2) as the active material. The device is capable of stable operation with good performance, and we demonstrate its use in feedback circuits including inverting amplifiers, integrators, log amplifiers and transimpedance amplifiers. We also show that our 2D platform can be used to monolithically integrate an analogue signal preconditioning circuit with a MoS2 photodetector. An operational amplifier that uses the two-dimensional semiconductor molybdenum disulfide as the active material can be used to create complex analogue circuits, including inverters, integrators and amplifiers.

Optimal Sizing of Recycling Folded Cascode Amplifier for Low-Frequency Applications Using New Hybrid Swarm Intelligence-Based Technique

ABSTRACT A new efficient design approach for sizing a high-performance analog amplifier circuit namely the recycling folded cascode (RFC) amplifier is presented. An RFC amplifier is an enhanced version of the conventional folded cascode amplifier and achieves better slew rate, gain, bandwidth, offset, etc. for same area and power budget. Low-frequency amplifiers such as biomedical or neural have a demanding requirement of low area, low power, and low noise apart from meeting other optimal design specifications which have inherent trade-off among themselves. As a result, manual sizing becomes a computationally inefficient approach. Thus, swarm-based optimization techniques have been employed to efficiently determine the optimal sizing for the RFC amplifier such that the area is minimized while meeting all the optimal design specifications considering the constraints. A new hybrid whale particle swarm optimization (HWPSO) algorithm is employed which takes advantage of the good qualities of both the whale algorithm and the PSO algorithm to optimize the area with less computational complexity. Simulations and statistical analysis have been performed and comparisons with other state of art algorithms reveals that HWPSO-based approach achieves a minimum circuit area of 21 µm2 with a mean Friedman’s statistical rank of 2.05 while meeting optimal design specifications for low-frequency systems. Finally, validation with circuit design tool Cadence Virtuoso is done and pre- as well as postlayout analysis have been performed which further illustrated a close agreement with algorithmic results.

The influence of energy recovery on the overall efficiency of acoustic sources at low frequencies

This paper defines a criterion called the overall efficiency (OE) for evaluating the efficiency of acoustic sources. In practice, the conventional efficiency (CE), is not capable of giving a comprehensive overview of the power consumption, especially in the connected amplifier drivers. The reason for this is that the CE is defined based on the nominal input electrical power. The nominal input electrical power is defined as the real part of the power that is delivered by the electrical amplifier to the actuation unit of an acoustic source. Therefore, power loss in the amplifier unit is not included in the CE definition. With the aid of the OE criterion, the effect of power loss in the connected amplifier units is taken into account. In particular, the application of the OE is crucial for acoustic sources that operate in a low frequency range. This is due to the reactive nature of power in both actuators and connected amplifiers. In the current paper, various combinations of amplifiers and actuators are studied. In particular, voice coil actuators and piezoelectric stack elements including both Lead Zirconate Titanate (PZT) ceramics and single crystal Lead Zirconate Niobate-Lead Titanate (PZN-PT) piezoelectric materials are investigated. In addition, the effect of a connected power driver is investigated. A class AB and a class D amplifier are studied respectively as analogue and switching amplifiers. Unlike a class AB amplifier, a class D amplifier is capable of energy recovery. A perforated flat acoustic source is examined in this paper as a practical example to verify the OE criterion. The numerical simulation on a thin acoustic source shows that for a single actuator, thanks to energy recovery, the OE is higher in a class D amplifier than that in a class AB amplifier. This study reveals that if a class D amplifier is the driver, using piezoelectric actuators results in a higher OE compared to using a voice coil actuator. Measurements on the sample acoustic source verify the numerical results presented in the current study.