- 标题
- 摘要
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- 实验方案
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Current linearity and operation stability in Al <sub/>2</sub> O <sub/>3</sub> -gate AlGaN/GaN MOS high electron mobility transistors
摘要： To investigate current linearity and operation stability of metal–oxide–semiconductor (MOS) AlGaN/GaN high electron mobility transistors (HEMTs), we have fabricated and characterized the Al2O3-gate MOS-HEMTs without and with a bias annealing in air at 300 °C. Compared with the as-fabricated (unannealed) MOS HEMTs, the bias-annealed devices showed improved linearity of ID–VG curves even in the forward bias regime, resulting in increased maximum drain current. Lower subthreshold slope was also observed after bias annealing. From the precise capacitance–voltage analysis on a MOS diode fabricated on the AlGaN/GaN heterostructure, it was found that the bias annealing effectively reduced the state density at the Al2O3/AlGaN interface. This led to efficient modulation of the AlGaN surface potential close to the conduction band edge, resulting in good gate control of two-dimensional electron gas density even at forward bias. In addition, the bias-annealed MOS HEMT showed small threshold voltage shift after applying forward bias stress and stable operation even at high temperatures.
关键词： current linearity,interface states,MOS-HEMT,AlGaN/GaN,operation stability,bias annealing
更新于2025-09-23 15:23:52
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mmWave CMOS Power Amplifiers for 5G Cellular Communication
摘要： This article covers the basics of millimeter-wave PA design in CMOS technology for integrated phased arrays, targeting the upcoming 5G new radio (NR) cellular communication standard. Key PA figures of merit, as well as application of beam-forming phased arrays to combine power over-the-air, are briefly reviewed. Then, starting from practical handset form factor constraints and system-level drivers, CMOS-specific technological and design-related challenges are conceptually illustrated using a simple single-transistor PA. A survey of the state-of-the-art is presented to give examples of the challenges and illustrate the PA techniques used to tackle them in linear 28-GHz CMOS PAs for 5G NR.
关键词： beam-forming,efficiency,linearity,millimeter-wave,power amplifier,phased array,CMOS,5G
更新于2025-09-23 15:22:29
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<i>(Invited)</i> Physics and Compact Modeling of SiGe HBT Linearity Using Mextram
摘要： This paper presents fundamentals of SiGe HBT RF linearity and its compact modeling using Mextram 504.12 and the latest Mextram, 505.00, for both common-emitter and common-base configurations. Collector-base junction depletion capacitance model is shown to be significant for accurate modeling of peak IP3 behavior, for which two new options are introduced in Mextram 505.00. Current dependence of avalanche factor is shown to be important for accurate modeling of IP3 peak. This is increasingly important in emerging RF applications requiring SiGe HBTs to operate at increasingly high VCB with negative IB.
关键词： SiGe HBT,compact modeling,IP3,RF linearity,Mextram,avalanche factor
更新于2025-09-23 15:21:01
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Performance study of LaBr3:Ce detectors coupled to R2083 PM tube for energy and timing characteristics
摘要： Performance of 1″ × 1″ LaBr3 (5% Ce) scintillator coupled to Hamamatsu R2083 PM Tube has been investigated for the first time. Energy response and timing characteristics of the present assembly have been studied at different operating conditions for its application in fast timing spectroscopy. An energy resolution of 3.38 ± 0.03% at 662?keV γ-energy was obtained in the present work at a bias voltage of ? 2800?V and a linear response could be observed up to a bias voltage of ? 2500?V. Time resolution of a single LaBr3:Ce crystal was found to be 174 ± 2?ps and 121 ± 3?ps for 511–511 and 1173–1332 cascades respectively. Effect of applied bias voltage on the time resolution of the set up was studied and a steady improvement with increasing bias voltage was observed. Present results were compared with the previous results obtained with similar fast PM tubes and importance as well as implications of the present measurement were also discussed.
关键词： Linearity,R2083 PMT,Scintillator,LaBr3:Ce,Energy,γ-ray,Resolution,Hamamatsu
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE 5G World Forum (5GWF) - Silicon Valley, CA, USA (2018.7.9-2018.7.11)] 2018 IEEE 5G World Forum (5GWF) - Long distance and high bandwidth wireless link tests for a 39 GHz to 28 GHz 5G low-cost repeater
摘要： This paper presents a low-cost millimeter-wave repeater for range extension in a 5G fixed wireless access system. It simply converts the wireless fronthaul signals in the 39 GHz band to the wireless access signals in the 28 GHz band without any base-band signal processing. Initial outdoor over-the-air tests with a simplified setup proved that a sufficient linearity can easily be achieved even over long fronthaul link length. Moreover, high bandwidth measurements with multi-carrier 5GTF pre-5G test signals demonstrated excellent EVM values with high signal-to-noise ratios enabling the required high data rates.
关键词： fixed wireless access,5G communication systems,linearity,millimeter-wave
更新于2025-09-23 15:21:01
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[IEEE 2019 International Aegean Conference on Electrical Machines and Power Electronics (ACEMP) & 2019 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM) - Istanbul, Turkey (2019.8.27-2019.8.29)] 2019 International Aegean Conference on Electrical Machines and Power Electronics (ACEMP) & 2019 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM) - Identifying Internal Defects of Photovoltaic Panels Using Sweep Frequency Response Analysis
摘要： In this paper, we propose a discrete-time IIR low-pass ?lter that achieves a high-order of ?ltering through a charge-sharing rotation. Its sampling rate is then multiplied through pipelining. The ?rst stage of the ?lter can operate in either a voltage-sampling or charge-sampling mode. It uses switches, capacitors and a simple gm-cell, rather than opamps, thus being compatible with digital nanoscale technology. In the voltage-sampling mode, the gm-cell is bypassed so the ?lter is fully passive. A 7th-order ?lter prototype operating at 800 MS/s sampling rate is implemented in TSMC 65 nm CMOS. Bandwidth of this ?lter is programmable between 400 kHz to 30 MHz with 100 dB maximum stop-band rejection. Its IIP3 is +21 dBm and the averaged spot noise is 4.57 nV/ Hz. It consumes 2 mW at 1.2 V and occupies 0.42 mm2.
关键词： switched capacitor,low power,high linearity,IIR,low-pass ?lter,low noise,recon?gurable,high order,real pole,discrete time,digital equalization,passive,CMOS
更新于2025-09-23 15:19:57
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Lateral scale calibration for focus variation microscopy
摘要： Areal surface texture measuring instruments can be calibrated by determining a set of metrological characteristics currently in the final stages of standardisation. In this paper, amplification, linearity and perpendicularity characteristics have been determined to calibrate the lateral performance of a focus variation microscope. The paper presents a novel and low-cost material measure and procedures that are used to determine the characteristics. The material measure is made of stainless steel with a cross-grating grid of hemispherical grooves. The design, manufacture and calibration of the material measure are discussed. The 20 × 20 mm grid is measured with and without image stitching. The results show that the proposed material measure and procedures can be used to determine the error of the amplification, linearity and perpendicularity characteristics. In addition, the lateral stage error can be significantly reduced by measurement with image stitching.
关键词： focus variation microscopy,amplification coefficient,lateral calibration,metrological characteristics,linearity deviation,perpendicularity deviation
更新于2025-09-19 17:15:36
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[IEEE 2018 International Conference on Advances in Computing, Communications and Informatics (ICACCI) - Bangalore (2018.9.19-2018.9.22)] 2018 International Conference on Advances in Computing, Communications and Informatics (ICACCI) - Cumulative Amplifier and Doppler Effect on PSK modulated signals in Inter-Satellite Communication
摘要： The paper brings out the cumulative effect of Doppler frequencies on Saleh type non-linearity for a PSK (Phase Shift Keying) modulated signal in Intersatellite communication link. The distortion introduced is measured by taking Error Vector Magnitude (EVM) as metric of evaluation. A PSK modulated signal is considered for study and the equation for the EVM is derived for the PSK signal affected with Doppler and Saleh type non-linearity. The Intersatellite links to be employed for the proposed constellation get affected with Doppler. The Doppler frequency changes with the frequency of operating signal. In this paper a time invariant Doppler is considered and its effect on the PSK signal is brought out. The PSK type considered is QPSK and the effect of amplifier linearity is first derived and then the effect of Doppler is applied onto it. The EVM expression derived is the power reference the EVM expression results are presented for variation of EVM with doppler frequency. From the results it can be observed that a) The EVM varies non-periodically with the Doppler frequency. b) The EVM value changes for different Saleh Parameters and changes with the Doppler frequency. The EVM values are found to worse for Saleh parameters that have higher values of slope in the amplifier characteristics.
关键词： Saleh model non-linearity,Cube Satellite-microsatellite constellation,Doppler and Phase error,Intersatellite Links
更新于2025-09-19 17:15:36
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[IEEE 2018 Asia-Pacific Microwave Conference (APMC) - Kyoto, Japan (2018.11.6-2018.11.9)] 2018 Asia-Pacific Microwave Conference (APMC) - 23-31GHz Low Noise Amplifier with 2.5dB NF Using 100 nm GaN on Silicon Technology
摘要： Gallium Nitride (GaN) high electron mobility transistors (HEMTs) have become good candidate for microwave power amplifier application. Furthermore, by combining the high power and the low noise performance, GaN HEMTs also show a great potential in high linearity low noise amplifier application. In this report, a four-stage low noise amplifier using commercial 100 nm GaN on Silicon Technology is presented. The designed LNA achieves a noise figure of 2.2-2.8 dB and a small signal gain of 25-29 dB from 23 to 31 GHz. The output 3-dB compression point (P3dB) is in the 17 dBm range. The LNA works with only one DC power supply and has a chip size of 2.3mm × 1mm. Compared with the existing Gallium Arsenic technology, this LNA has higher gain, higher linearity while keeping the noise figure at the same level.
关键词： GaN on silicon,Linearity,Low-noise amplifier
更新于2025-09-19 17:15:36
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[IEEE 2019 IEEE 19th International Conference on Nanotechnology (IEEE-NANO) - Macao (2019.7.22-2019.7.26)] 2019 IEEE 19th International Conference on Nanotechnology (IEEE-NANO) - Injection Lock Frequency Divider with Class-C Coupled VCO for Nanoelectronics Harmonic Demodulator of Fluxgate Sensing
摘要： This paper presents a 9-bit 1.8 GS/s pipelined analog-to-digital converter (ADC) using open-loop amplifiers. In this ADC, open-loop amplifiers are used as residue amplifiers to increase the sampling rate of the ADC with relatively low power consumption. A linearization technique is proposed to suppress the SNDR decrease caused by the nonlinearity of open-loop amplifiers. The attenuation in the capacitor digital-to-analog converter (CDAC) is utilized to calibrate the gain error of the pipelined stages. In addition, top-plate sampling is proposed to further enhance the power efficiency of the residue amplifiers. With these techniques, the ADC achieves a high sampling rate and high power efficiency. A prototype of the ADC is fabricated in 65 nm CMOS technology. An SNDR of 47 dB and a FoM of 134 fJ/conversion-step is achieved at a sampling rate of 1.8 GS/s with 900 MHz input, while consuming 44 mW from a 1.2 V supply.
关键词： double sampling,open-loop amplifier,linearity enhancement,Analog-to-digital converter,pipelined ADC
更新于2025-09-19 17:13:59