Performance Of Amplifier Research Articles

Common Source Amplifier and Ring Oscillator Circuit Performance Optimization Using Multi-Bridge Channel FETs

In this paper the DC, analog/RF device and circuit applications of nanosheet (NS) FET is performed. To enhance power performance co-optimization geometry parameters like NS width (NSW) and NS thickness (NSH) are varied for high performance (HP) and low power (LP) applications. A rise in 1.47x in I ON and a rise of 5.8x in I OFF is noticed with increase in NSH due to enlarged effective width (W eff). In addition, a rise of 3.8x in I ON and a fall of 76.4% in I OFF is noticed with higher NSW. Larger the NSW ensures better transconductance (gm), transconductance generation factor (TGF), cut-off frequency (f T), gain-band width product (GBW), transconductance frequency product (TFP), and intrinsic delay (τ). The optimized supply voltage (V DD) for maximum voltage gain of common source (CS) amplifier and 3 stage ring oscillators (RO) with varied NSW is performed. Moreover, the impact of number of stages (N) of 3 stage RO for better frequency of oscillations (f OSC) is studied towards high frequency circuit applications.

Parametric amplification and instability in time-periodic dielectric slabs.

We study the phenomenon of parametric amplification in the context of time-periodic dielectric slabs. These structures show particular promise inasmuch as they are capable of very large amplifications when illuminated by an electromagnetic wave of half the modulation frequency. Successive studies have corroborated this finding but none have yet been able to ascertain the nature of amplification in such devices. On top of that, some studies have raised speculations regarding the instability of a time-periodic slab which are off the mark. The problem lies in the poor understanding (or lack thereof) of the mathematical devices necessary to tackle such problems. We successfully carry out the tasks by tapping into the rich mathematical theory of Hill's equation. Specifically, we make use of the Folquet's theorem in its complete form which brings to light novel physical phenomena that the more prevalent simplified form fails to account for. Also, useful mathematical concepts such as coexistence are employed which to the best of our knowledge have not yet been applied in the field of time-varying optics. Our analytical method proves an effective means of assessing the amplifier's performance, e.g., estimating how long it takes for the device to reach steady state. We further delineate the link between amplification and instability and correct the misconceptions surrounding the subject by presenting a rigorous analysis of the instability problem in such structures.

A 40% PAE and 34dBm Peak OIP3 CMOS Power Amplifier with Integrated Zero Power Consumption Phase Linearizer

In this paper, an Integrated Phase Linearizer (IPL) technique is designed to improve the linearity performance of a CMOS power amplifier (PA). The IPL is integrated at the gate of the PA so that the effect of the parasitic gate-to-source ([Formula: see text]) capacitance of the main transistor is compensated by the linearizer. Thus, it improves the 3rd-order intermodulation point (OIP3) without trading-off the power added efficiency (PAE). The proposed solution is designed and fabricated in an 180[Formula: see text]nm CMOS technology process consuming the chip area of 2.25[Formula: see text]mm2. At the operating frequency of 2.45[Formula: see text]GHz, it exhibits a gain of 11.14[Formula: see text]dB with unconditional stability characteristics from 1[Formula: see text]GHz to 10[Formula: see text]GHz. Biased quiescent current of 19.35[Formula: see text]mA, the IPL-PA delivers a maximum output power of 15.20[Formula: see text]dBm with 40.86% peak PAE, 34.91[Formula: see text]dBm of peak OIP3 and maximum power consumption of 63.65[Formula: see text]mW at 2.45[Formula: see text]GHz with supply voltage headroom of 1.8[Formula: see text]V. The proposed linearization scheme proved to be an excellent solution for low-power transceivers integration.

Characterization of Traveling-Wave Josephson Parametric Amplifiers at T = 0.3 K

The growing interest in quantum technologies, from fundamental physics experiments to quantum computing, demands for extremely performing electronics only adding the minimum amount of noise admitted by quantum mechanics to the input signal (i.e., quantum-limited electronics). Superconducting microwave amplifiers, due to their dissipationless nature, exhibit outstanding performances in terms of noise (quantum limited), and gain. However, bandwidth and saturation power still show space for substantial improvement. Within the DARTWARS <xref ref-type="fn" rid="fn1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">¹</xref> <fn id="fn1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><label>¹</label> DARTWARS (Detector Array Readout with Traveling Wave AmplifieRS), funded by Italian National Nuclear Institute (INFN), is a quantum technologies project targeted at the development of wideband superconducting amplifiers with noise at the quantum limit and the implementation of a quantum-limited readout in different types of superconducting detectors and qubit. </fn> collaboration, we are developing state-of-the-art microwave superconducting amplifiers based on Josephson junction arrays and on distributed kinetic inductance transmission lines. Here we report the realization of a setup for the characterization of the performances of Josephson traveling-wave parametric amplifiers at a temperature of 300 mK. Although in the final experimental setup, these amplifiers will operate at a base temperature of about 20 mK, their characterization at 300 mK allows to evidence the main aspects of their performances, but the ultimate noise level. This represents a quick and relatively inexpensive way to test these superconductive devices that can be of help to improve their design and fabrication.

A large-signal scaling model of high-power GaN microwave device

With the rapid development of wireless communications, GaN HEMT, which has various advantages of high power density, high electron mobility, and high breakdown threshold, receiving increasing attention. Microwave power amplifiers based on GaN HEMTs are widely used in many fields, such as communication, medical, and detection instruments. In the accurate design of GaN microwave power amplifiers, reliable RF large signal model is vitally important. In this paper, a scalable large-signal model based on EEHEMT model is proposed to describe the properties of multifinger AlGaN/GaN high electron mobility transistor (HEMT) accurately. A series of scaling rules is established for the intrinsic parameters of the device, including drain-source current &lt;i&gt;I&lt;/i&gt;&lt;sub&gt;ds&lt;/sub&gt;, input capacitance &lt;i&gt;C&lt;/i&gt;&lt;sub&gt;gs&lt;/sub&gt; and &lt;i&gt;C&lt;/i&gt;&lt;sub&gt;gd&lt;/sub&gt;, which take into account both the gate width of a single finger and the number of gate fingers. With the proposed scalable large-signal model, the performance of the L-band GaN high-efficiency power amplifier with a gate length of 14.4 mm is analyzed. This amplifier demonstrates outstanding performance, with the output power reaching to 46.5 dBm and the drain efficiency arriving at over 70% of the frequency range from 1120 MHz to 1340 MHz. Good agreement between the simulations and experiments is achieved, demonstrating the excellent accuracy of the proposed model. Moreover, the proposed model can further predict the performance of high-order harmonics, providing an effective tool for designing advanced high-power and high-efficiency microwave power amplifiers. Certainly, the EEHEMT model fails to characterize the dynamical behavior induced by trapping and self-heating effects. Thus, for further consideration, scaling models for the thermal resistance and heat capacity need further investigating to broaden the application scope of the proposed model in the case of continuous waves.

Research progress of lock-in amplifiers

The lock-in amplifier can perform high-precision measurement in both time and amplitude dimensions, so that it becomes a key component of instrumental system for precision measurement and control. This article overviews the concept, technology, and application of phase-locked amplifiers as a guide. It first explains the development and evolution of phase-locked amplifiers of analog, digital, and virtual phase-locked amplifiers, demonstrating their relationship and differences. Then, it classifies phase-locked amplifiers from a mathematical perspective based on the order and type of phase-locked loops. Subsequently, the testing process and metrological calibration progress of the main performance of phase-locked amplifiers, such as amplitude, frequency, and phase noise, are introduced. The conversion relationship between key indicators such as phase noise, time-domain jitter, Allan variance, and the coupling relationship with amplitude noise are discussed. Finally, the application forms and effects of phase-locked amplifiers in the fields of spectral enhancement, impedance analysis, magnetic measurement, microscopic imaging, and space exploration are listed. Through some new applications, the prospects of their transition from scientific instruments to industrial and even civilian products through intelligent computing, precise IoT, and other means are briefly given.

Holographic Back-Projection Method for Calibration of Fully Digital Polarimetric Phased Array Radar

Phased Array Radar (PAR) technology is rapidly rising as a candidate for future weather radars because it can provide focused, high-quality meteorological observations. Due to the need for precise measurements of polarimetric weather variables, it is desired that the radar simultaneously transmits and receives linearly polarized horizontal (H) and vertical (V) fields through beams that are well matched in gain and shape at every pointing direction. These scanning characteristics are difficult to achieve, especially with current methods such as the “park and probe” calibration, because the radiation patterns of PAR antennas are inherently dependent on their pointing direction. Thus, polarimetric array calibration is critical to produce matched H/V copolar antenna patterns. In this article, we present a polarimetric antenna calibration procedure for the fully-digital PARs based on the holographic back-projection of electric fields. The fully digital S-band Horus radar is used to implement and evaluate the proposed calibration method. First, near-field measurements of a fully active Horus antenna panel are back-projected onto the plane of the array to derive the copolar magnitude and phase of the H/V fields radiated by each antenna element. Then, digital calibration parameters are produced from back-projected fields to compensate for excitation differences and produce uniform radiation at the plane of the array. The performance of the back-projection calibration method is evaluated for broadside and for electronically scanned angles and compared to the more conventional park and probe calibration method. A robustness analysis is conducted using simulations to evaluate the impact of excitation amplitude and phase errors that could result from practical near-field environments and amplifier performance degradation. Preliminary results show that through precise digital calibration based on back-projected fields, beam matching can be significantly improved to achieve the desired polarimetric calibration levels. For electronically steered beams, back-projection calibration can reduce H/V beam mismatch biases by approximately 25%, from 0.34 dB to 0.08 dB. This improves measurement accuracy of fully digital PARs by mitigating antenna-induced biases in meteorological estimates.

Компьютерный символьный анализ и исследование сигнальных характеристик СВЧ-интегрального трансимпедансного усилителя на КМОП-транзисторах

A technique is proposed for investigating and designing microwave transimpedance amplifiers (TIAs) based on the joint use of computer symbolic analysis and CMOS-transistors' linear equivalent circuits (ECs). The technique makes it possible to analyze the influence of various schematic parameters on TIA performances using automatically generated analytical expressions as well as to obtain recommendations for amplifier design. The investigation of the influence of devices' EC elements helps to choose CMOS-transistors' constructions and sizes when designing integrated TIAs. The approach proposed is applied to the input stage of microwave common source-common drain TIA with parallel feedback. The analysis of dependences of the main TIA characteristics (transimpedance, group delay, and input/output impedances) on circuit elements and transistor parameters is performed. Also, the amplifier stability is investigated. It is shown that, in contrast to the commonly used TIA analysis based on idealized models of active elements, the proposed approach provides sufficient accuracy in calculating amplifier performances up to the frequency of 30 GHz.

A Micropower High-Performance ECG Recording Amplifier

This work introduces a novel micropowered single supply low-noise ECG amplifier that can be used with dry fabric-based paste-less electrodes for ambulatory electrocardiogram monitoring. The study emphasizes the need to include realistic values of source impedance as high as 10 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{M}\Omega $ </tex-math></inline-formula> to assess amplifier performance parameters, such as magnitude response, time-domain response, common-mode input impedance, semiconductor noise, and common mode rejection ratio (CMRR). The effect on these parameters associated with high values of electrode impedance at different input frequencies has been extensively demonstrated in this work. The recommendations and standards published by the International Electrotechnical Commission (IEC) 60601 pertaining to electrocardiographic equipment have been used to evaluate the performance requirements of the amplifier to ensure minimal distortion of the ECG signal. The amplifier attains a minimum common-mode input impedance of 10 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{G}\Omega $ </tex-math></inline-formula> at the input within a frequency range of 0.1–150 Hz. This boosted input impedance is preserved by neutralizing amplifier input capacitance using power supply bootstrapping. The amplifier also maintains a differential gain of 41 dB, the CMRR was measured at 84 dB at mains frequency, and the input referred semiconductor noise was measured at 32- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{V}$ </tex-math></inline-formula> peak-to-peak ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> Vpp) in a bandwidth of 250 Hz. The power consumption of the amplifier was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$130 ~\mu \text{W}$ </tex-math></inline-formula> operating from 3.7-V lithium battery and is intended to provide for ECG signals having amplitudes in the range 0.1–10 mV. This small portable amplifier is intended for use in long-term ECG and heart-rate monitoring applications.

Effect of CNT Parameter Variations on CNTFET Amplifier Performance

In this paper we propose a procedure to study the dependence of a CNTFET amplifier performance on CNT parameters that fully identify the geometrical properties of a regular CNT. In particular these parameters are the length and structural indices (n,m) of CNT. We analyse the effects on a linear common source amplifier using a N type CNTFET with a resistive gate polarization. We polarize at a fixed drain voltage and current, gradually changing the CNT parameters. As regards the indices, we present the analysis for a zig-zag CNT. However the proposed procedure can be applied to other types of CNT. We show the effect on gain, on the 3 dB cut off frequency, F3dB, on the input and output resistances, obtaining that F3dB has a clear inverse dependence on the length and that also decreases at higher structural indices for zig-zag CNT.

Effects of L-shape and Raman second-order pumping scheme on the performance of double-pass hybrid fiber amplifier

Effects of L-shape and Raman second-order pumping scheme on the performance of double-pass hybrid fiber amplifier

Gain Modeling and Numerical Simulation of Fiber Amplifier

As optical communication technology has been developing fast these years, its application in S-band has been valued by people, especially in the field of WDM/DWDM. The energy structure-e in Tm3+exist the transition which can meet the S-band and S+-band. Although the energy structure of ions are very complex, the fiber amplifier is an important device for the S+-band optical amplification. And its research will be very significant for further broadening the optical communication bandwidth. Fiber amplifiers have become a new hot spot for optical fiber communication devices. This paper mainly do analysis, simulation and comparison about the semiconductor laser mufti-core pigtail outputting light field intensity, as well as the outputting light field intensity distribution of LD mufti-core pigtail single-lens and dual-lens coupled. This paper analyzes fiber amplifier performance based on the rate equation, transfer equation and simulations.

THE WORKING PRINCIPLE OF OPTICAL AMPLIFIERS AND THEIR TYPES

One of the most important components of optical communication systems is optical amplifiers. By improving the performance of optical amplifiers, we will be able to achieve the optimality of the entire network. This article describes optical amplifiers and their types.

Frequency Compensation Network for Three-Stage CMOS Operational Amplifier

The rapid advancements of CMOS integrated circuits technologies lead designers to cascade structures and avoiding cascode amplifiers. As a result, frequency compensation becomes the most important issue since multi-stage amplifiers are highly potential to instability. Here in this work, two differential stages are exploited to form frequency compensation network. These stages realize four Miller loops and share each Miller capacitor in two loops simultaneously. This intensifies Miller effect to improve frequency response due to pole-zero cancellation. The proposed three stage amplifier is modeled symbolically via a transfer function (TF) while 0.18um CMOS technology is used for circuit simulation. Good agreement between theoretical calculation and simulation results shows validity and accuracy of the TF. Also ample simulations are performed to exhibit the proposed amplifier performance against parameters mismatches. The proposed three stage amplifier expresses 105 dB as DC-gain, 4.8 MHz as Gain Band Width and 72 degree as Phase Margin. The amplifier consumes 360 uW as power consumption. This performance obviously is an improvement of Nested Miller Compensation (NMC) while Figure of Merits (FoMs) are enhunced.

Temperature drift mechanism of deflector jet servo valve under temperature shock

To study the mechanism of the deflector jet servo valve under temperature shock, a complete temperature theoretical model is proposed in this article. The temperature change affects the performance change of the torque motor by affecting the drift of the air gaps’ thickness, the permanent magnets’ reluctance, and the magnetomotive polarization force. Moreover, the temperature variation will act on the flow coefficient of the pilot stage, the size of the deflector, and jet pan, which influences the performance of the pilot stage hydraulic amplifier. Furthermore, the armature components, including the stiffness of the spring tube, the stiffness of the feedback rod, and the armature’s arm of force, are also related to the temperature variation. Comprehensively, considering the interaction influence of these factors, by analyzing the electromagnetic characteristics of the torque motor, the fluid mechanics’ characteristics of the pilot stage hydraulic amplifier, and the temperature performance of the armature assembly, the temperature drift model of deflector jet servo valve is constructed, which is represented as a ninth-order nonlinear equation. Based on the equation, the influence of temperature on the control precision of the servo valve is analyzed. The calculation results show that in the range of 20°C–250°C, the impact of temperature on the control accuracy will exceed 30%, the flow coefficient is the most significant affecting on the control accuracy, followed by the structural deformation of the pilot stage is the second factor affecting the temperature drift, and other factors have little effect. Comparison with the experimental results, the temperature drift model of the deflector jet servo valve can predict the control accuracy caused by temperature and provide a theoretical foundation for the optimization of the deflector jet servo valve.

Implementation of class‐E/F3 power amplifiers based on the variations of the MOSFET grading coefficient, built‐in potential and output capacitance along with their roles in MOSFET selectivity

SummaryIn this paper, a theoretical analysis of the class‐E/F3 power amplifier based on the variation of the grading coefficient m1 and its vital role in MOSFET selectivity to operate safely under given design specifications is presented while the nonlinearity of the drain‐to‐source capacitance is considered. Moreover, the importance of Vbi and Cjo in designing the class‐E/F3 amplifier is investigated. To clarify how the grading coefficient m1 and the other mentioned parameters can directly influence the power amplifier performance and also its elements, these MOSFET parameters are considered as the independent variables of the calculated equations and consequently define the horizontal axis of the obtained plots. Accordingly, as the grading coefficient increases, the maximum switch voltage increases and values of the output power and output power capability decline. Moreover, to prove the reliability of the carried‐out analysis in selecting proper MOSFETs, the performances of three amplifier samples utilizing IRF510, IRFZ24N, and 2SK2504 MOSFETs with different grading coefficient m1 and almost similar Vbi and Cjo are studied. Then, by comparing the results of amplifiers with three MOSFETs, IRF510, IRF530, and IRF540, with similar grading coefficient and different values of Vbi and Cjo, the significance of considering the values of Vbi and Cjo is investigated. Eventually, three amplifiers with 2SK2504, IRF510, and IRF530 MOSFETs have been simulated, implemented, and tested and measurement results agreed well with the theoretical and simulation results.

The Gain performance of Ytterbium Doped Fiber Amplifier

Ytterbium doping provides high capacity for producing large gain per unit length, and versatility in pump optimization for a given gain length .The paper presents gain characteristic of Ytterbium doped Fiber Amplifier in terms of amplifier length, Yb ion density, pump power and signal power at pump wavelength λp =910 nm and signal wave length λs =975 nm s. A maximum gain of (39, 37 and 33dB) obtained for pump powers (150, 100 and 50 mw). The gain occurs over short length (tenth of centimeters) of the amplifier and increase with increasing Yb ion density. It begins to be moderately saturated when ion concentration exceeds 1.3 e+025. After certain pump power gain values become saturated while it decreases rapidly by increasing signal power. As a result of laboratories unavailability in the region the layout done by using Optisystem 8.0 software simulation (Optical Amplifier and Communication System Design Software)

A Millimeter-Wave CMOS Series-Doherty Power Amplifier With Post-Silicon Inter-Stage Passive Validation

This article presents a wideband series-Doherty power amplifier (SDPA) for millimeter-wave (mm-wave) fifth-generation (5G) applications. It features a compact two-step impedance inverting-based series-Doherty power combiner that provides broadband close-to-perfect power back-off (PBO) efficiency enhancement. The amplitude-to-amplitude (AM–AM)/amplitude-to-phase (AM–PM) performance of the load-modulated Doherty power amplifier for broadband operation is analyzed. We also devise a post-silicon inter-stage passive validation (PSIV) approach to evaluate the mm-wave chip prototype utilizing the embedded voltage root mean square detectors. The proposed SDPA is realized in a 40-nm bulk CMOS, and it delivers 20.4 dBm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\text {SAT}}$ </tex-math></inline-formula> with 39.1%/34% PAE at 0-/6-dB PBO. Over a 23.5–30 GHz band, its PAE is >24% at 6-dB PBO. At 27 GHz, applying a “2 GHz 16-quadratic-amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM)” signal, the proposed SDPA generates 10.2 dBm average power with 18.9% average PAE. The average error vector magnitude is better than −24.5 dB without digital predistortion for a “400-MHz 64-QAM OFDM” signal while generating an average output power of 8.8 dBm with 15% PAE. The AM–AM/AM–PM of the realized SDPA is investigated by employing a “50-MHz 64-QAM OFDM” signal, validating our analysis and showing that the linearity limitation of DPAs is systematic and predictable. Utilizing the proposed PSIV approach, the frequency response of the input/inter-stage passive circuits is measured, indicating an excellent agreement with 3-D electromagnetic (EM) simulation results.

Conventional/linear/Lorentzian material gain semiconductor optical amplifiers performance signature with four wave mixing (FWM) nonlinearity in optical fiber communication systems

Abstract This study demonstrates the FWM nonlinearity effects on fiber systems based on conventional/linear/Lorentzian material gain wide band traveling wave semiconductor optical amplifiers (WBTWSOAs) at data rates of 10 Gbps. Max signal power (MSP) and noise power (NP) levels are illustrated versus time and SW after WDM multiplexer. The MSP and min NP are clarified against time and SW based conventional, linear, Lorentzian material gain WBTWSOAs. The total optical power after WDM multiplexer, and the total optical power based conventional, linear, Lorentzian material gain WBTWSOAs are measured. Max Q versus time after receiver based WDM multiplexer, and max Q versus time after receiver based conventional, linear, Lorentzian material gain WBTWSOAs are reported clearly in this study. Besides the max Q against CS is studied with/without FWM effects. Nonlinear coefficient, conversion efficiency is analyzed clearly against fiber length without/with FWM effects.

The Dickson Charge Pump as a Signal Amplifier

In this paper it is proposed and explored the use of the Dickson charge pump (CP) to amplify time-variant signals. The study has been carried out through a theoretical analysis that provides an in-depth comprehension of the behavioral equations and the main design metrics commonly used to evaluate the performance of amplifiers. Starting from the analytical models, we show the conditions upon which the CP can be modeled with an equivalent small signal circuit and can amplify a signal. Then, assuming the CP working in the widest operative conditions, small-signal, large-signal and noise analysis are carried out. The results have been validated by extensive simulations and measurements on a proof of concept using a 130 nm CMOS technology.