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20?W 1952?nm tandem hybrid single and double clad TDFA
摘要： A simple engineering design is important for achieving high Thulium-doped ampli?er (TDFA) performance such as good power conversion, low noise ?gure (NF), scalable output power, high gain, and stable operation over a large dynamic range. In this paper we report the design, performance, and simulation of two stage high-power 1952 nm hybrid single and double clad TDFAs. The ?rst stage of our hybrid ampli?er is a single clad design, and the second stage is a double clad design. We demonstrate TDFAs with an output power greater than 20 W with single-frequency narrow linewidth (i.e. MHz) input signals at both 1952 and 2004 nm. An optical 10 dB bandwidth of 80 nm is derived from the ASE spectrum. The power stage is constructed with 10 μm core active ?bers showing a maximum optical slope e?ciency greater than 50%. The experimental results lead to a 1 dB agreement with our simulation tool developed for single clad and double clad TDFAs. Overall this hybrid ampli?er o?ers versatile features with the potential of much higher output power.
关键词： Simulation,Fiber ampli?er,Multistage,Single frequency,Fiber measurement,Thulium
更新于2025-09-23 15:23:52
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Preparation of ultra-broadband antireflective coatings for amplifier blast shields by a sol–gel method
摘要： A type of λ/4–λ/4 ultra-broadband antire?ective coating has been developed using modi?ed low refractive silica and high refractive silica layers by a sol–gel dip coating method for ampli?er blast shields of the Shen Guang II high power laser facility (SG-II facility). Deposition of the ?rst layer (high refractive index silica) involves baking at 200 ?C in the post-treatment step. The second layer (low refractive index, n = 1.20) uses low refractive index silica sol modi?ed by acid catalysis. Thermal baking at temperatures no less than 500 ?C for 60 min offers chemical stability, ethanol scratch resistance, and resistance to washing with water. The average residual re?ection of dual-side-coated fused silica glass was less than 1% in the spectral range from 450 to 950 nm. Transmission gain has been evaluated by taking into account angular light, and the results show that the transmission gain increases with increasing light incidence. Even at 60?, the transmission spectrum of the broadband antire?ective coating effectively covered the main absorption peak of Nd:glass.
关键词： blast shields,ampli?er,ultra-broadband,sol–gel,antire?ective coating
更新于2025-09-23 15:21:21
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[Communications in Computer and Information Science] Advances in Computing and Data Sciences Volume 905 (Second International Conference, ICACDS 2018, Dehradun, India, April 20-21, 2018, Revised Selected Papers, Part I) || Assessing the Performance of CMOS Amplifiers Using High-k Dielectric with Metal Gate on High Mobility Substrate
摘要： With the increase in demand for high-performance ICs for both memory and logic applications, scaling has been continued down to 14 nm node. To meet the performance requirements, high-k dielectrics such as HfO2, ZrO2 have replaced SiO2 in the conventional MOS structure for sub-45 nm node. Correspondingly, the polysilicon gate electrode has been replaced by metal gate electrode in order to enable integration with high-k. Furthermore, the standard silicon substrate has been replaced by high mobility substrate in order to obtain desired transistor performance. While the fabrication technology for CMOS has advanced rapidly the traditional design tools used for designing circuits continues to use conventional MOS structure and their properties. This paper aims to analyze frequency response of CMOS common source ampli?er(CSA) and di?erential ampli?er by simulating in MATLAB using metal gate/high-k/Ge structure and to compare with traditionally used ampli?er design using standard MOS structure.
关键词： CMOS - Complementary Metal Oxide Semiconductor,EOT - E?ective Oxide Thickness,CSA - Common Source Ampli?er,UGB - Unity Gain Bandwidth,High-k dielectrics based ampli?er design
更新于2025-09-23 15:21:01
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High-power long-wave infrared laser based on polarization beam coupling technique
摘要： We demonstrated a high-power long-wave infrared laser based on a polarization beam coupling technique. An average output power at 8.3 μm of 7.0 W was achieved at a maximum available pump power of 107.6 W, corresponding to an optical-to-optical conversion of 6.5%. The coupling ef?ciency of the polarization coupling system was calculated to be approximately 97.2%. With idler single resonance operation, a good beam quality factor of ～1.8 combined with an output wavelength of 8.3 μm was obtained at the maximum output power.
关键词： optical parametric ampli?er,long-wave infrared laser,polarization coupling,optical parametric oscillator
更新于2025-09-23 15:21:01
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A 28-GHz Low-Power Vector-Sum Phase Shifter Using Biphase Modulator and Current Reused Technique
摘要： In this letter, we present a low-power vector-sum phase shifter for upcoming 5G communication at 28 GHz. The ±I/±Q signals for phase synthesis by vector adder (VA) are generated by a 90° coupler and two re?ection-type biphase modulators. Modulators are only biased at 0 and 1.8 V to avoid large insertion loss near their phase reversal region. Our proposed single-ended two branches quadrature structure can avoid the differential variable gain ampli?er and achieve low power and compact area. In addition, we use the current reused technique to connect VA and output buffer to save dc power and suppress a change in output impedance among different phase states. The measured average peak gain is ?3.75 dB at 29.25 GHz. Across all phase states, the measured IP1 dB is better than 5 dBm. The 3-dB bandwidth of S21 is 27–33 GHz. Input and output return losses are also better than 10 dB at this frequency range. Total dc power consumption is only 6.6 mW for 1.8 V supplied voltage. To the best of our best knowledge, this phase shifter has low dc power and compact area at K-band and Ka-band.
关键词： vector adder (VA),phase-invertible variable attenuators (PIVAs),Biphase modulator (BM),current reused technique,vector-sum phase shifter (VSPS),buffer ampli?er (BA)
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE BiCMOS and Compound semiconductor Integrated Circuits and Technology Symposium (BCICTS) - Nashville, TN, USA (2019.11.3-2019.11.6)] 2019 IEEE BiCMOS and Compound semiconductor Integrated Circuits and Technology Symposium (BCICTS) - A Compact Ka-Band Transformer-Coupled Power Amplifier for 5G in 0.15um GaAs
摘要： In this paper we present the design of a compact and broadband transformer-coupled power ampli?er in a 0.15μm GaAs technology. The power ampli?er achieves an output power of 26.5dBm and 31% power added ef?ciency, 12.6dB of small signal gain with a fractional bandwidth of 40%. The ampli?er enables up to 21.6dBm, 19.9dBm of average output power while amplifying a 6Gb/s, 9Gb/s 64-QAM signal respectively at 28GHz with an EVM<-25dB without any digital pre-distortion. To the author’s knowledge, this is the ?rst time transformer-coupled matching networks are used in a GaAs power ampli?er leading to very compact matching structures compared to bulky transmission line.
关键词： 5G,Power Ampli?er,Millimeter wave integrated circuits,Transformer-Coupled,Ka-band
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - The Impact of Deposition Temperature on Sodium Fluoride Recrystallization in Cu(In,Ga)Se <sub/>2</sub> Solar Cells
摘要： Modi?cation of a previously described rotational unipolar induction experiment leads to a rectilinear version of the same, in which the induction of an electromotive force can be obtained independently of the relative motion between magnet and conductor, even when both are moving in a straight line. This experiment seems to contradict the usual relativistic canon that motional electromagnetic induction always requires relative motion between conductors and magnets. The theoretical and practical consequences of the new experiment are discussed.
关键词： electromagnetic motional induction,Differentiating ampli?er,RC R circuit,relativity theory
更新于2025-09-23 15:19:57
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[IEEE 2018 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS) - San Diego, CA, USA (2018.10.15-2018.10.17)] 2018 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS) - A 1–20 GHz Distributed, Stacked SiGe Power Amplifier
摘要： This paper presents a wideband distributed power ampli?er that operates from 1-20 GHz. The peak output power is 19.5 dBm, with a peak PAE of 28% at 1 GHz. The power ampli?er utilizes a distributed ampli?er topology with arti?cial transmission lines, as well as transistor stacking, to achieve high output power and wide bandwidth. For the ampli?er core power cells, a stack-up of four SiGe HBTs was used to distribute the maximum voltage swing across the ampli?er. This power ampli?er, designed in a 90 nm SiGe BiCMOS platform, occupies an area of 1.95×1.3mm2.
关键词： wideband,SiGe HBTs,PAE,distributed power ampli?er,transistor stacking
更新于2025-09-23 15:19:57
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A broadband GaAs pHEMT low noise driving amplifier with current reuse and self-biasing technique
摘要： A K/Ka-band two-stage low noise driving ampli?er using a 0.15 lm GaAs pHEMT for low noise technology is designed and fabricated. In order to achieve broadband driving capability with low power consumption, current reuse technique is adopted to feed both transistors with the same DC power supply, which theoretically cuts the total current consumption in half. In addition, self-biasing technique is utilized to minimize both external power supply pads and chip footprint, which reduces the number of supply pads to a minimum of two (1 power pad and 1 ground pad). The circuit topology analysis and design procedures are also presented with an emphasis on noise ?gure and P1dB optimization. The low noise driving ampli?er demonstrates a - 3 dB bandwidth of wider than 11 GHz, a power gain of 17 dB, an in-band mean noise ?gure of 2.2 dB and an in-band mean output P1dB of 6 dBm. The DC power consumption is 9.1 mA@3.3 V power supply. The chip size is 1 mm 9 1.5 mm with only 1 external DC feed pad (3.3 V) and 1 ground pad (0 V). With the performance comparable to typical two-stage dual-bias low noise driving ampli?er counterparts, the proposed MMIC is more attractive to chip/system users in volume-limited and power-contrained applications.
关键词： Ka-band,Pseudomorphic high electron mobility transistor (pHEMT),GaAs,Low noise driving ampli?er,Monolithic microwave integrated circuit (MMIC)
更新于2025-09-19 17:15:36
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Wideband Hybrid Envelope Tracking Modulator With Hysteretic-Controlled Three-Level Switching Converter and Slew-Rate Enhanced Linear Amplifier
摘要： A wideband hybrid Envelope tracking (ET) modulator utilizing a hysteretic-controlled three-level switching converter (3L-SWC) and a slew-rate enhanced linear ampli?er (LA) are presented. In addition to smaller ripple and lower losses of 3L-SWCs, employing the proposed hysteresis control results in a higher speed loop and wider bandwidth converter, enabling over 80 MHz of switching frequency. A concurrent sensor circuit monitors and regulates the ?ying capacitor voltage VCF and eliminates the conventionally required calibration loop to control it. The hysteretic-controlled 3L-SWC provides a high percentage of power ampli?er (PA) supply load current with lower ripple, reducing the LA high-frequency current and ripple cancellation current, improving the overall system ef?ciency. A slew-rate enhancement (SRE) circuit is employed in the LA, resulting in slew rate of over 307 V/μs and bandwidth of over 275 MHz for the LA. The SRE circuit provides a parallel auxiliary current path directly to the gate of the class-AB output stage transistors, speeding-up the charging or discharging of output without modifying the operating point of the remaining LA, while maintaining the quiescent current of the class-AB stage. The supply modulator is fabricated in a 65-nm CMOS process. The measurement results show the tracking of long-term evolution (LTE)-40-MHz envelope with 93% peak ef?ciency at 1-W output power, while the SRE is disabled. Enabling the SRE, it can track LTE-80-MHz envelope with peak ef?ciency of 91%.
关键词： long-term evolution (LTE),LTE-advanced,hysteresis control,Envelope tracking (ET),supply modulator,power ampli?er (PA),three-level switching converter (3L-SWC),slew-rate enhancement (SRE),hybrid
更新于2025-09-19 17:13:59