Band Amplifier Research Articles

On the Extraction of Accurate Non-Quasi-Static Transistor Models for E-Band Amplifier Design: Learning From the Past

On the Extraction of Accurate Non-Quasi-Static Transistor Models for <i>E</i>-Band Amplifier Design: Learning From the Past

Er3+/Yb3+ Co-Doped Fluorotellurite Glass Fiber with Broadband Luminescence.

In order to address the 'capacity crisis' caused by the narrow bandwidth of the current C band and the demand for wide-spectrum sensing sources and tunable fiber lasers, a broadband luminescence covering the C + L bands using Er3+/Yb3+ co-doped fluorotellurite glass fiber is investigated in this paper. The optimal doping concentrations in the glass host were determined based on the intensity, lifetime, and full width at half maximum (FWHM) of the fluorescence centered at 1.5 µm, which were found to be 1.5 mol% Er2O3 and 3 mol% Yb2O3. We also systematically investigated this in terms of optical absorption spectra, absorption and emission cross-sections, gain coefficients, Judd-Ofelt parameters, and up-conversion fluorescence. The energy transfer (ET) mechanism between the high concentrations of Er3+ and Yb3+ was summarized. In addition, a step-indexed fiber was prepared based on these fluorotellurite glasses, and a wide bandwidth of ~112.5 nm (covering the C + L bands from 1505.1 to 1617.6 nm) at 3 dB for the amplified spontaneous emission (ASE) spectra has been observed at a fiber length of 0.57 m, which is the widest bandwidth among all the reports based on tellurite glass. Therefore, this kind of Er3+/Yb3+ co-doped fluorotellurite glass fiber has great potential for developing broadband C + L band amplifiers, ultra-wide fiber sources for sensing, and tunable fiber lasers.

All-optical output power stabilization of double-clad Er:Yb amplifiers using 1064 nm signal injection

We present a novel technique for all-optical stabilization of the output power of telecom band amplifiers based on double-clad (DC) erbium-ytterbium (Er:Yb) doped fibers. The proposed method relies on the utilization of the undesirable energy back-transfer effect which occurs in DC Er:Yb active fibers. A feedback loop is built based on a low-power 1064 nm laser, which is coupled into the Er:Yb fiber along with the 1550 nm seed. The auxiliary 1 µm signal partially extracts the Yb-ion energy, altering the gain at the design wavelength. The stabilization technique was verified for two types of fibers, to demonstrate the feasibility of our approach regardless of the type of DC Er:Yb fiber used, its characteristics, and the amplifier configuration. A long-term stability improvement by a factor of 117 was achieved, reaching a deviation of 0.8 µ W, for 100 s integration time.

Comparative study of single pump all optical fiber amplifiers (POAs) with ultra wide band and high gain fiber optic parametric amplifiers in highly nonlinear fibers

Abstract This paper has clarified comparative study of single pump all optical fiber amplifiers with ultrawide band and high gain fiber optic parametric amplifiers in highly nonlinear fibers. Different amplifiers gain is demonstrated versus system distance for different light amplifiers in highly nonlinear fiber channel. As well as amplifier gain is clarified against system distance for different light amplifiers in DCF, DSF and NZDSF fiber channel. The mechanism of generation of single idler signal is studied based on single signal and pump signal. Moreover the mechanism of generation of single idler signal is analyzed and investigated clearly based on signal and two pump signals. Amplifier bandwidth is demonstrated against system distance for different fiber channel types in the presence of POA amplifiers based on 100 mW, 300 mW and 500 mW pumping power. The map of the signal losses is discussed and clarified versus wavelength band in the presence of all amplification techniques. Light signal per noise ratio and bit error rates are demonstrated against system distance for different fiber channel types in the presence of POA amplifiers based on 100 mW, 300 mW and 500 mW pumping power. POA is more suitable for the operation in HNLF fiber channel in compared to other proposed fiber communication channels. All optical amplifiers operation performance gain efficiency is compared together in different fiber channel media. The system can be employed with POAs for the fiber reach up to 100 km distance with a suitable amplifier gain and bandwidth. An important criteria for any amplifier is its gain and bandwidth for the compensation of the system loss and dispersion together. The optimum suitable pumping power is clarified for upgrade the system amplifier performance signature.

High efficiency coupling fibers with different types of photo detectors for the management of noise multiplication and efficient bandwidth

Abstract This work has clarified the high efficiency coupling fibers with different types of photo detectors for the management of noise multiplication and efficient bandwidth. As well as the study of the base band signal to noise base band form ratios are clarified with EDFA base band amplifier length variations. Max Q form factor with EDFA amplifier base band length variations is also demonstrated. The optimum base band electrical signal form power is simulated with EDFA base band amplifier length variations. The simulative study of Ge and InGaAs PIN photo-detectors performance evaluation are studied in the presence of the soliton transmission fiber systems. The dispersion management by the soliton technique to reach the value around zero. The max base band signal power form is clarified versus time based Ge and InGaAs PIN photo-detectors. Total base band electrical power form based Ge and InGaAs PIN photo-detectors are demonstrated. Max signal base form power amplitude band is simulated with the spectral base band frequency based Ge and InGaAs PIN photo-detectors. The max signal base form power amplitude band is studied versus time based Ge PIN photo-detectors.

The Propagation of Extended SET Tails in RF Amplifiers Using 45-nm CMOS on PDSOI

The propagation of long-duration single-event transient (SET) tails in radio frequency (RF) amplifiers implemented with SOI CMOS was investigated using laser pulses to emulate heavy ion strikes. Transients were recorded and analyzed in CMOS transistors, a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">K_u</i> -band amplifier, and a broadband amplifier. At the device-level, transient modifications to small-signal transconductance were confirmed in TCAD, but these changes were found to be insignificant for practical transistor sizings found in RF amplifiers. In RF amplifiers, filtering due to matching networks and regulation from negative feedback were found to reduce potential system-level sensitivities to these transient tails. Body-contacting was shown to reduce transient amplitude, at the cost of amplifier performance, but its application in eliminating the transient tail is likely only worthwhile in DC-coupled amplifiers. Selection of pMOS over nMOS transistors was also confirmed to reduce transient amplitude, but with no benefit to transient duration. The present work demonstrates that body-contacting can reduce transient amplitude at the cost of RF performance, but no benefit in transient duration is expected at the amplifier-level for many cases.

Study of the Frequency Self-Modulation in Gyro-TWT Based on Two -Band Amplifiers

Periodical radiation spectrum with a frequency difference of ~160 MHz is observed in hot-test experiments of Ku-band gyrotron traveling-wave tubes (gyro-TWTs). By the means of eigenmode analyses and particle-in-cell (PIC) simulation considering the whole output transition section from the interaction circuit end to the output window, we found that the circuit oscillation is pronounced because of frequency self-modulation (FSM). As a comparison, the cutoff taper contributing to the FSM is removed and a new amplifier has been developed; hot-test results indicate that the periodical property has been greatly alleviated as expected and the stability of the amplifier is well improved.

Assessment of optical and fluorescence aspects of Er3+-doped multicomponent B2O3 glasses as active media for 1.532 μm near-infrared optical amplifiers

Current work principally provides an idea on controlling the Er3+: NIR (near-infrared) emission characteristics by changing a glass constituent and finding a suitable glass host favorable to design a novel C-optical band (1.53–1.565 μm) amplifier. By melting and rapid quench route, six transparent Er3+ (1 mol%)-doped B2O3-rich glasses having different single and mixed alkali ions were fabricated, and optical and fluorescence (visible and NIR) traits including Er3+ ion upper-levels 4S3/2 and 4I13/2 decay dynamics were inspected for such samples. At 1.4–1.65 μm wavelength range, an intense and wide NIR luminescence band centered at 1.532 μm (Er3+: 4I13/2 → 4I15/2 transition) has been obtained by a 980 nm laser diode pumping (4I15/2 → 4I11/2). NIR fluorescence Δλeff (effective bandwidth) varied depending on added single or mixed alkali ions, and a maximum Δλeff ∼74.66 nm was acquired for Er3+: Li ions constituting glass. For the 4I13/2 → 4I15/2 transition, σemi (stimulated emission cross-section) was evaluated using both Füchtbauer–Ladenburg and McCumber's theories. In all glasses, comparably, higher gain bandwidth (= 5.384 × 10−26 cm3) and peak σemiM (= 1.692 × 10−20 cm2) values have been attained for 4I13/2 → 4I15/2 transition in Li ions containing sample, and also this glass possesses the largest σabs (absorption cross-section) (= 1.459 × 10−20 cm2) for 4I15/2 → 4I13/2 transition. Further, at distinctive P (population inversion) values, gain spectra were computed, and all samples show C-optical band amplification beginning from P = 50%. All analyzed NIR fluorescence results indicate that Li ions having glass could be a potential gain medium for fiber amplifiers.

Broadband Performance of a 6W Pushpull Power Amplifier on the VHF-UHF Band

In this paper, a broadband 100-700 MHz power amplifier was designed. The results of simulation are compared with the measurements,The shunt feedback of power amplifier module provides the linear and broadband frequency amplification. The push-pull topology with ferrite balun provides enhanced efficiency and high power generation along In this work a commercially available LDMOS transistor (D2003UK) is used, The amplifier can deliver 6W to a 50 ohm load and has 14dB gain.Broadband high power amplifiers are considered as key components in next generation software defined radio communication systems. In principle, application of a linear, highly efficient wide band amplifier can replace several narrow band power amplifiers, yielding reduced costs and form factor, This paper uses D2003UK a transistor to achieve a 6 Watt amplifier for broad band .

Design of a bandgap reference voltage source with low temperature coefficient and high precision

This paper proposes a high-precision, low-temperature coefficient, and repair-free bandgap reference power supply circuit. This kind of bandgap reference source adopts the way of double-loop feedback, namely through two amplifiers to clamp the voltage to improve the performance of the circuit. The band gap reference source is mainly composed of four parts, including: band gap reference core circuit, amplifier, start-up circuit and Gaussian current compensation circuit. This article mainly analyzes the working principle of the core circuit of the bandgap reference, and derives the mathematical formula of the circuit. When the power supply voltage is 1.8V, the circuit is simulated in the temperature range of -40°C to 125°C with the Hspice software, and the reference source outputs stably. The voltage is 1.25V±4mv, the temperature coefficient is 3.7ppm/°C, and PSRR at low frequencies is -68dB.

Characterization Technique to Reveal Critical Resonances in Nonlinear RF Circuits

The presence of critical resonances can significantly impact the stable and robust operation of microwave amplifiers, leading to spurious oscillations in the worst case. In this work, a technique based on noise measurements performed with a spectrum analyzer is presented to experimentally characterize these resonances. Broadband white noise is injected into the input of the circuit, so the critical resonances are clearly revealed above the noise floor of the measuring instrument, without the need of exigent settings and far from the bifurcation point. In addition to detecting potentially risky resonances, the actual position of the critical poles on the pole-zero map can be estimated from these noise measurements by applying pole-zero identification techniques. The noise injection technique has been tested in two nonlinear prototypes in microstrip technology: an analog frequency divider and an <inline-formula> <tex-math notation="LaTeX">${L}$ </tex-math></inline-formula>-band amplifier.

Additive Manufacturing of a Wideband Capable W-Band Packaging Strategy

In this letter, we demonstrate a fully additively manufactured packaged $W$ -band amplifier with integrated bypass capacitors. This package was fabricated using a chip-first approach and aerosol jet printing (AJP). Package substrates (dielectrics), conductors, and interconnects are printed around a bare die attached to a carrier. This package uses shaped ramp interconnects, allowing for frequency agnostic performance of the interconnect with no impedance discontinuity, within the physical limits of the printer. High dielectric constant thin films of a polymer-matrix nanocomposite for bypass capacitors were printed using multimaterial AJP. The maximum measured packaged gain is 14.9 dB in the $W$ -band compared to the maximum bare die gain of 15.5 dB in the same frequency range. From 75 to 92 GHz, the average package loss is 1.1 dB including 3-mm transmission line, interconnects, and a ground-signal-ground (GSG) launch structure correlating to an average loss of 0.37 dB/mm.

A D-Band High-Gain and Low-Power LNA in 65-nm CMOS by Adopting Simultaneous Noise- and Input-Matched G max-Core

This article proposes a high-gain and low-power low-noise amplifier (LNA) by adopting a simultaneous noise- and input-matched (SNIM) maximum achievable gain ( G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ) core. The G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> -core is implemented by adjusting the infinite combinations of embedding networks with three passive elements. Based on the proposed two-port noise analysis for implementing the G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> -core, the input stage G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> -core can achieve a simultaneous power gain and noise matching. The adoption of the G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> -core in the input stage can maximize the amount of gain per stage, leading to higher total power gain and lower noise figure (NF). The two-stage 150-GHz LNA adopting the SNIM G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> -core is implemented in a 65-nm CMOS process. The measurement results show a peak gain of 17.9 dB at 152.2 GHz, 3-dB bandwidth of 11 GHz, NF of 4.7 and 6.2 dB at 148 and 150 GHz, respectively, and a peak power added efficiency (PAE) of 7.7% while dissipating only 13.73 mW. This work shows the highest gain per stage and the lowest NF with the lowest dc power consumption among other reported CMOS D-band amplifiers.

Design and Analysis of a Wideband Staggered Double-Vane Slow-Wave Structure for W-Band Amplifier

This article presents the design and analysis of a staggered double-vane (SDV) slow-wave structure (SWS) for $W$ -band amplifier, with 20-dB gain and a very high bandwidth (~25%). The use of dual Bragg reflector at either end of the interaction structure increases the impedance matching and the radio frequency (RF) coupling efficiency at the input and output ports, thereby reducing the RF leakage at the electron gun and collector ends, from 15% to 25% to less than 0.6%. The attenuator section is simple to fabricate and optimally designed in order to provide an effective isolation (>20 dB) between the input RF signal in the input section and the RF signal reflected from the output section. The dispersion analysis, the transmission analysis of each section, and the beam–wave interactions were simulated using the Dassault system’s computer simulation technology (CST) eigenmode solver, time-domain solver, and the particle-in-cell (PIC) solver, respectively. The proposed design of the SDV SWS conclusively provides an enormous bandwidth of ~25 GHz with 20-dB gain for $W$ -band amplifier, when compared to its solid-state counterparts and earlier reported work as per the author’s knowledge.

Gain‐flattened hybrid EDFA operating in C + L band with parallel pumping distribution technique

A novel C + L band hybrid erbium-doped fibre amplifier (EDFA) using a two-stage configuration was proposed and demonstrated experimentally. The amplifier is composed of a 0.5-m long hafnium bismuth erbium co-doped fibre (EDF) to provide gain within the C-band and a 4-m long zirconia-based EDF to provide gain within the L-band. The proposed amplifier was examined based on the multi-wavelength input source. A parallel pumping distribution technique was used to mitigate the amplifier complexity. The C + L band amplifier achieved a gain flattening of over 55 nm bandwidth for the three levels of the input powers. A gain-flattening of roughly 10.9, 15.5, and 19.2 dB were obtained, respectively, for the input signal powers of −5, −10, and −15 dBm. An average noise figure of 6.4, 5.4, and 4.7 dB was achieved, respectively, for the input signal powers of −5, −10, and −15 dBm.

A Capacitive SIW Discontinuity for Impedance Matching

We present a shunt capacitive substrate-integrated waveguide (SIW) discontinuity for the first time. The discontinuity is parametrically characterized in terms of its reactive impedance, and an equivalent circuit model is presented and validated. $C$ -band prototypes are manufactured and measured, confirming the simulated results. The utility of the discontinuity is then demonstrated as a part of a matching network for an $S$ -band amplifier. A simple synthesis method for the matching networks is presented, which requires minimal numerical optimization. The amplifier is prototyped and measured and found to be in good agreement with simulation.

An efficient L-band Zirconia Yttria Aluminum Erbium co-doped fiber amplifier with 1480nm pumping

The optical amplification performance of the proposed Zirconia Yttria Aluminum Erbium co-doped fiber (Zr-EDF) was compared for two different pumping schemes; 1480 and 980[Formula: see text]nm. An efficient [Formula: see text]-band amplifier was achieved using 3[Formula: see text]m length of Zr-EDF while 1480[Formula: see text]nm pumping is found to provide higher attainable gain and better noise figure as compared to 980[Formula: see text]nm pumping. At a pumping wavelength of 1480[Formula: see text]nm and an input signal power of [Formula: see text]10[Formula: see text]dBm, the proposed amplifier provides a relatively flat-gain of about 13.3[Formula: see text]and 17.3[Formula: see text]dB with single-pass and double-pass configuration, respectively, where the gain variation was less than 1[Formula: see text]dB within a wavelength region of 1560–1600[Formula: see text]nm. The noise figures of the proposed Zr-EDFA were maintained below 8 and 14.5[Formula: see text]dB for single-pass and double-pass arrangement, respectively, within the flat-gain region. Compared to the conventional amplifier configured with silica based erbium-doped fiber amplifier, the proposed Zr-EDF-based amplifier achieves a higher and flatter gain and lower noise figure at [Formula: see text]-band region even though it uses a shorter length of gain medium.

Active Dual-Band Power Divider and Active Quad-Plexer Based on Traveling Wave Amplification and D-CRLH Transmission Line

A travelling wave structure with two novel functionalities is presented in this brief. The structure benefits from the nonlinear dispersion relation of dual-composite right/left-handed (D-CRLH) transmission line (TL). It consists of two distributed amplifiers (DAs) that have one common gate line and two drain lines. The conventional microstrip TL is used for gate line while the D-CRLH unit cells (UCs) are used to make the drain TLs. When the operating frequencies of D-CRLH TLs of both drain lines are the same, the structure acts as a directional dual-band active power divider (PD). The RF input signal depending on the input signal frequency, is divided into two forward or reverse output ports after amplification. If the D-CRLH TLs have different operating frequencies with no common band, the structure can act as an active quad-plexer or directional quad band amplifier. In this situation, four amplified signals with different frequency bands can be extracted from four different physical output ports. Analysis and design procedure of the structure is provided and a fabricated prototype is measured which shows a good agreement between the simulated results and the measurement results.

Nonlinear Distortion Noise and Linear Attenuation in MIMO Systems—Theory and Application to Multiband Transmitters

Nonlinear static multiple-input multiple-output (MIMO) systems are analyzed. The matrix formulation of Bussgang's theorem for complex Gaussian signals is rederived and put in the context of the multivariate cumulant series expansion. The attenuation matrix is a function of the input signals’ covariance and the covariance of the input and output signals. The covariance of the distortion noise is in addition a function of the output signal's covariance. The effect of the observation bandwidth is discussed. Models of concurrent multiband transmitters are analyzed. For a transmitter with dual non-contiguous bands expressions for the normalized mean square error (NMSE) vs input signal power are derived for uncorrelated, partially correlated, and correlated input signals. A transmitter with arbitrary number of non-contiguous bands is analysed for correlated and uncorrelated signals. In an example, the NMSE is higher when the input signals are correlated than when they are uncorrelated for the same input signal power and it increases with the number of frequency bands. A concurrent dual band amplifier with contiguous bands is analyzed; in this case the NMSE depends on the bandwidth of the aggregated signal.

Wideband Techniques for Outphasing Power Amplifiers

In this paper a wideband, high-power amplifier that achieves an output power of 20 W with a bandwidth greater than one octave in the L and S bands is presented. Two ~10 W Class AB PAs are implemented with Gallium Nitride-high electron mobility transistor devices and a low loaded-Q matching network to achieve wideband performance. High power added efficiency (PAE) is achieved by combining outphased saturated power amplifiers using a wideband isolated combiner. We introduce new analysis detailing proper selection of the isolation resistance in isolated outphasing combiners. The impedance transforming Wilkinson combiner is designed to interface the system with a 50- $\Omega $ load. The L-S band (1.2~2.5GHz) amplifier was simulated, fabricated, and characterized. The fabricated HPA provides a peak output power of 43 dBm, gain of >15 dB with a peak PAE of >40% across the band. A 10 MHz, 64 QAM, long-term evolution signal is measured and achieves ACLR < −30 dBc, EVM = 4.8%-rms at an average output power and efficiency of 39.3 dBm and 33.1%, respectively.