Sub-millimeter-Wave Equivalent Circuit Model for External Parasitics in Double-Finger HEMT Topologies

We present a novel distributed equivalent circuit that incorporates a three-way-coupled transmission line to accurately capture the external parasitics of double-finger high electron mobility transistor (HEMT) topologies up to 750 GHz. A six-step systematic parameter extraction procedure is used to determine the equivalent circuit elements for a representative device layout. The accuracy of the proposed approach is validated in the 90–750 GHz band through comparisons between measured data (via non-contact probing) and full-wave simulations, as well as the equivalent circuit response. Subsequently, a semi-distributed active device model is incorporated into the proposed parasitic circuit to demonstrate that the three-way-coupled transmission line model effectively predicts the adverse effect of parasitic components on the sub-mmW performance in an amplifier setting.     

A coplanar X-band AlGaN/GaN power amplifier MMIC on s.i. SiC substrate

This work presents a two-stage high-power amplifier monolithic microwave integrated circuit (MMIC) operating between 9 GHz and 11 GHz based on a fully integrated AlGaN/GaN high electron mobility transistor (HEMT) technology on s.i. SiC substrate and is suitable for radar applications. The MMIC device with a chip size of 4.5/spl times/3 mm/sup 2/ yields a linear gain of 20 dB and a maximum pulsed saturated output power of 13.4 W at 10 GHz equivalent to 3.3 W/mm at V/sub DS/=35V, 10% duty cycle, and a gain compression level of 5 dB. Further, dc reliability data are given for the MMIC HEMT technology.     

An approach to determining an equivalent circuit for HEMTs

A simple way to determine a small-signal equivalent circuit of High Electron Mobility Transistors (HEMTs) is proposed. Intrinsic elements determined by a conventional analytical parameter transformation technique are described as functions of extrinsic elements. Assuming that the equivalent circuit composed of lumped elements is valid over the whole frequency range of the measurements, the extrinsic elements are iteratively determined using the variance of the intrinsic elements as an optimization criterion. Measurements of S-parameters up to 62.5 GHz at more than 100 different bias points confirmed that the HEMT equivalent circuit is consistent for all bias points     

30 nm T-gate enhancement-mode InAlN/AlN/GaN HEMT on SiC substratesfor future high power RF applications

The DC and RF performance of 30 nm gate length enhancement mode (E-mode) InAlN/AlN/GaN high electron mobility transistor (HEMT) on SiC substrate with heavily doped source and drain region have been investigated using the Synopsys TCAD tool. The proposed device has the features of a recessed T-gate structure, InGaN back barrier and Al₂O₃ passivated device surface. The proposed HEMT exhibits a maximum drain current density of 2.1 A/mm, transconductance g_m of 1050 mS/mm, current gain cut-off frequency f_t of 350 GHz and power gain cut-off frequency f_max of 340 GHz. At room temperature the measured carrier mobility (μ), sheet charge carrier density (n_s) and breakdown voltage are 1580 cm²/(V·s), 1.9×10¹³ cm^-2, and 10.7 V respectively. The superlatives of the proposed HEMTs are bewitching competitor or future sub-millimeter wave high power RF VLSI circuit applications.     

A multigigahertz Josephson-semiconductor interface circuit using77-K differential monolithic HEMT amplifier and 4.2-K JJ high-voltagedriver for superconductor-semiconductor electronic hybrid systems

We proposed and successfully demonstrated a high-speed Josephson IC to semiconductor IC output interface circuit combining a high electron mobility transistor (HEMT) amplifier and Josephson high-voltage drivers successfully. We developed a 0.5-μm gate 77-K wide-band analog monolithic HEMT amplifier for the interface. The HEMT device consisted of InGaP/InGaAs materials stable even at 77 K. The amplifier has a differential amplifier as a first stage to cancel out ground-level fluctuations in the Josephson IC and showed a voltage gain of 23 dB and ~3-dB frequency of 8 GHz. A 0.63-V_p-p output was obtained from a 5-GHz, 30-mV_p-p complementary input signal. We succeeded in transfer ring a voltage signal from 10-stack Josephson high-voltage drivers to a 50-Ω system at room temperature with 0.7-V_p-p amplitude at 300-MHz clock using the HEMT amplifier     

（英）D波段InP基高增益、低噪声放大芯片的设计与实现

利用90-nm InAlAs/InGaAs/InP HEMT工艺设计实现了两款D波段（110~170 GHz）单片微波集成电路放大器。两款放大器均采用共源结构,布线选取微带线。基于器件A设计的三级放大器A在片测试结果表明：最大小信号增益为11.2 dB@140 GHz,3 dB带宽为16 GHz,芯片面积2.6×1.2 mm2。基于器件B设计的两级放大器B在片测试结果表明：最大小信号增益为15.8 dB@139 GHz,3dB带宽12 GHz,在130~150 GHz频带范围内增益大于10 dB,芯片面积1.7×0.8 mm2,带内最小噪声为4.4 dB、相关增益15 dB@141 GHz,平均噪声系数约为5.2 dB。放大器B具有高的单级增益、相对高的增益面积比以及较好的噪声系数。该放大器芯片的设计实现对于构建D波段接收前端具有借鉴意义。     

W-band InP HEMT MMICs using finite-ground coplanar waveguide(FGCPW) design

In this paper, we report on the development of W-band monolithic microwave integrated circuit (MMIC) power amplifiers using 0.1-μm AlInAs/GaInAs/InP high electron mobility transistor (HEMT) technology and finite-ground coplanar waveguide (FGCPW) designs. In the device modeling, the Angelov nonlinear HEMT model was employed to predict the large signal performance of the device, and the results were validated by using state-of-the-art vector load-pull measurements. A two-stage single-ended W-band FGCPW MMIC using a 150-μm-wide HEMT as the driver and a 250-μm-wide HEMT for the output stage was designed, fabricated, and tested. The MMIC amplifier demonstrates a maximum output power of 18.6 dBm with 18.2% power-added efficiency and 10.6 dB associated gain at 94 GHz. This result is the best output power to date reported from an InP-based MMIC using FGCPW design at this frequency     

A novel monolithic HBT-p-i-n-HEMT integrated circuit with HBTactive feedback and p-i-n diode variable gain control

We report the world's first functional MMIC circuit integrating HBT's, HEMT's, and vertical p-i-n diodes on a single III-V substrate. The 1-10 GHz variable gain amplifier monolithically integrates HEMT, HBT, and vertical p-i-n diode devices has been fabricated using selective MBE and a merged processing technology. The VGA offers low-noise figure, wideband gain performance, and good gain flatness over a wide gain control range. A noise figure below 4 dB was achieved using a HEMT transistor for the amplifier stage and a wide bandwidth of 10 GHz. A nominal gain of 10 dB was achieved by incorporating HBT active feedback techniques and 12 dB of gain control range was obtained using a vertical p-i-n diode as a varistor, all integrated into a compact 1.5×0.76 mm² MMIC. The capability of monolithically integrating HBT's, HEMT's, and p-i-n's in a merged process will stimulate the development of new monolithic circuit techniques for achieving optimal performance as well as provide a foundation for high performance mixed-mode multifunctional MMIC chips     

P波段3kW GaN功率器件的研制

介绍了一款高压高功率GaN功率器件及其匹配电路。基于国内高压GaN高电子迁移率晶体管(HEMT)的研究基础,选取了GaN HEMT芯片,确定了器件的总栅宽。根据GaN HEMT芯片阻抗,器件内部进行了LC谐振匹配设计,外部采用双边平衡同轴巴伦进行推挽匹配设计。散热方面通过改善封装管壳热沉材料提高热导率。最终成功研制出高压、3 kW的GaN功率器件,该器件在工作电压为60 V、工作频率为0.35~0.45 GHz、脉宽为300μs、占空比为10%条件下,频带内输出功率大于3 kW、功率增益大于16 dB、功率附加效率大于71%、抗负载失配能力不小于10∶1。     

微波功率器件的扇形线测试电路

在微波电路原理和半导体器件物理的基础上,设计和模拟了两种用于微波功率器件的测试电路,并且设计了与之配套的测试夹具.采用矢量网络分析仪对该测试电路和夹具在3～8GHz范围内进行了小信号测试.模拟和测试结果都表明,采用扇形线的测试电路性能较好.最后采用该电路和夹具对C波段AlGaN/GaN HEMT微波功率器件进行了微波功率测试,测试频率为5.4GHz.实验测得最大功率增益为8.75dB,最大输出功率为33.2dBm.     

微波功率器件的扇形线测试电路

在微波电路原理和半导体器件物理的基础上,设计和模拟了两种用于微波功率器件的测试电路,并且设计了与之配套的测试夹具.采用矢量网络分析仪对该测试电路和夹具在3～8GHz范围内进行了小信号测试.模拟和测试结果都表明,采用扇形线的测试电路性能较好.最后采用该电路和夹具对C波段AlGaN/GaN HEMT微波功率器件进行了微波功率测试,测试频率为5.4GHz.实验测得最大功率增益为8.75dB,最大输出功率为33.2dBm.     

Large-signal time-domain simulation of HEMT mixers

A large-signal HEMT (high electron mobility transistor) model and a time-domain nonlinear circuit analysis program have been developed. A systematic method to simulate HEMT mixers and design them for maximum conversion gain is presented. The transconductance-compression effect reduced the mixer's conversion gain at high frequencies. Simulation results from mixers designed to operate at 10, 20, and 40 GHz show that a reduction in parasitic conduction in the AlGaAs layer significantly increases the conversion gain     

GaAs Dual-Gate FET for Operation Up to K-Band

A high-frequency equivalent circuit model of a GaAs dual-gate FET and analytical expressions for the input/output impedances, transconductance, unilateral gain, and stability factor are presented in this paper. It is found that the gain of a dual-gate FET is higher than that of a single-gate FET at low frequency, but it decreases faster as frequency increases because of the capacitive shunting effect of the second gate. A dual-gate power FET suitable for variable gain amplifier applications up to K-band has been developed. At 10 GHz, a I.2-mm gatewidth device has achieved an output power of 1.1 W with 10.5-dB gain and 31-percent power-added efficiency. At 20 GHz, the same device delivered an output power of 340 mW with 5.3-dB gain. At K-band, a dynamic gain control range of up to 45 dB was obtained with an insertion phase change of no more than +-2 degrees for the first 10 dB of gain control.     

Monolithic HEMT-HBT integration by selective MBE

We have achieved successful monolithic integration of high electron mobility transistors and heterojunction bipolar transistors in the same microwave circuit. We have used selective molecular beam epitaxy and a novel merged processing technology to fabricate monolithic microwave integrated circuits that incorporate both 0.2 μm gate-length pseudomorphic InGaAs-GaAs HEMTs and 2 μm emitter-width GaAs-AlGaAs HBTs. The HEMT and HBT devices produced by selective MBE and fabricated using our merged HEMT-HBT process exhibited performance equivalent to devices fabricated using normal MBE and our baseline single-technology processes. The selective MBE process yielded 0.2 μm HEMT devices with g_m=600 mS/mm and f_T=70 GHz, while 2×10 μm² HBT devices achieved β>50 and f_T=21.4 GHz at J_c=2×10⁴ A/cm². The performance of both a 5-10 GHz HEMT LNA with active on-chip HBT regulation and a 20 GHz Darlington HBT amplifier are shown to be equivalent whether fabricated using normal or selective MBE     

An effective parameter extraction method based on memetic differential evolution algorithm

This paper provides an effective method for parameter extraction of microelectronic devices and elements. A novel method, memetic differential evolution (MDE) algorithm, is proposed in this paper. By combining differential evolution (DE) algorithm, mutations in immune algorithm (IA), and special operators for parameter extraction, MDE possesses characteristics of high accuracy, stability, generality, and efficiency. The effectiveness of the method has been shown by two typical examples, including small-signal equivalent circuit models for an AlGaN/GaN HEMT device up to 40 GHz, as well as an equivalent circuit model for on-chip differential spiral inductors. In both cases, the initial values and parameter ranges of the elements in the equivalent circuits are hard to determine in optimization. The results and comparisons with Levenberg-Marquardt (LM) algorithm, genetic algorithm (GA), particle swarm optimization (PSO) algorithm and canonical DE algorithm, demonstrate the superiority of MDE in terms of accuracy and generality.     

A monolithic DC temperature compensation bias scheme for multistageHEMT integrated circuits

This work benchmarks the first demonstration of a multistage monolithic HEMT IC design which incorporates a DC temperature compensated current-mirror bias scheme. This is believed to be the first demonstrated monolithic HEMT bias scheme of its kind. The active bias approach has been applied to a 2-18 GHz five-section low noise HEMT distributed amplifier which achieves a nominal gain of 12.5 dB and a noise figure <2.5 dB across a 2-18 GHz band, The regulated current-mirror scheme achieves better than 0.2% current regulation over a 0-125°C temperature range, The RF gain response was also measured over the same temperature range and showed less than 0.75 dB gain degradation. This results in a -0.006 dB/°C temperature coefficient which is strictly due to HEMT device G_m variation with temperature. The regulated current-mirror circuit can be employed as a stand-alone V_gs-voltage reference circuit which fan be monolithically applied to the gate bias terminal of existing HEMT ICs for providing temperature compensated performance, This monolithic bias approach provides a practical solution to DC bias regulation and temperature compensation for HEMT MMICs which can improve the performance, reliability, and cost of integrated microwave assemblies (IMAs) used in space-flight military applications     

AlGaN/GaN高电子迁移率晶体管小信号等效电路的参数提取

本文在高电子迁移率晶体管(HEMT)小信号等效电路模型的基础上,考虑了AlGaN/GaN HEMT的结构特性,具体分析了寄生参数和本征参数的提取方法.采用这些方法,实际测量了5～10 GHz频率下HEMT器件的小信号S参数并提取了它的电学参数,S参数的计算值与实际测量值进行了比较.实验结果表明此方法简单易行,较为精确.     

X波段30W内匹配GaN HEMT功率器件

采用自主研发的SiC衬底GaN HEMT外延材料,研制了总栅宽为2mmGaN HEMT,利用负载牵引系统测试器件的阻抗特性,得出该器件源漏阻抗实部分别为6Ω和22Ω;设计并制作了四管芯合成器件的阻抗匹配网络,在频率为8GHz下测试,饱和输出功率为30W,功率增益在6dB以上,功率附加效率为38%,该结果目前在国内为首次报道。     

Very high efficiency V-band power InP HEMT MMICs

State-of-the-art power performance of a V-band InP HEMT MMIC is reported using a slot via process for reducing source inductance and a fully selective gate recess process for uniformity and high yield. The 0.1 μm gate length, high performance InGaAs/InAlAs/InP HEMTs that were utilized in the circuit exhibited a maximum power density of 530 mW/mm, power added efficiency of 39%, and a gain of 7.1 dB. At 60 GHz, a single-stage monolithic power amplifier achieved an output power of 224 mW with a PAE of 43%. The associated gain was 7.5 dB. These results are the best combination of output power and efficiency reported for an InP device and a MMIC at V-band, and clearly demonstrates the potential of the InP HEMT technology for very high efficiency, millimeter wave power applications     

蓝宝石衬底上槽栅型X波段增强型AlGaN/GaN HEMT

研制了一款X波段增强型AlGaN/GaN高电子迁移率晶体管(HEMT)。在3英寸(1英寸=2.54 cm)蓝宝石衬底上采用低损伤栅凹槽刻蚀技术制备了栅长为0.3μm的增强型AlGaN/GaN HEMT。所制备的增强型器件的阈值电压为0.42 V,最大跨导为401 mS/mm,导通电阻为2.7Ω·mm。器件的电流增益截止频率和最高振荡频率分别为36.1和65.2 GHz。在10 GHz下进行微波测试,增强型AlGaN/GaN HEMT的最大输出功率密度达到5.76 W/mm,最大功率附加效率为49.1%。在同一材料上制备的耗尽型器件最大输出功率密度和最大功率附加效率分别为6.16 W/mm和50.2%。增强型器件的射频特性可与在同一晶圆上制备的耗尽型器件相比拟。