一个8GHz高功率AlGaN/GaN HEMT VCO

基于中科院微电子所的AlGaN/GaN HEMT工艺研制了一个X波段高功率混合集成压控振荡器（VCO）。电路采用源端调谐的负阻型结构,主谐振腔由开路微带和短路微带并联构成,实现高Q值设计。在偏置条件为VD=20V, VG=-1.9V, ID=150mA时,VCO在中心频率8.15 GHz处输出功率达到28 dBm,效率21%,相位噪声-85 dBc/Hz@100 KHz,-128 dBc/Hz@1 MHz。调谐电压0~5V时,调谐范围50 MHz。分析了器件闪烁噪声对GaN HEMT基振荡器相位噪声性能的主导作用。测试结果显示了AlGaN/GaN HEMT工艺在高功率低噪声微波频率源中的应用前景。     

一个8 GHz基于AlGaN/GaN HEMT的内匹配电路

论述了一个在8 GHz下基于AlGaN/GaN HEMT功率放大器HMIC的设计、制备与测试.该电路包含了1个10×100 μm的AlGaN/GaN HEMT和输入输出匹配电路.在偏置条件为VDS=40 V、IDS=0.16 A时输出连续波饱和功率在8 GHz达到36.5 dBm(4.5 W),PAE为60%,线性增益10 dB;在偏置条件为VDS=30 V、IDS=0.19 A时输出连续波饱和功率在8 GHz达到35.6 dBm(3.6 W),PAE为47%,线性增益9 dB.     

8W AlGaN/GaN HEMT功率器件的研制

报道了基于国产衬底以及国产外延的AlGaN/GaN HEMT X波段功率器件的研究进展.利用国产衬底以及外延材料,优化了器件栅场板的结构,研制成功栅长0.35μm,栅宽为lmm的微波功率器件.该器件输出电流密度达到0.83A/mm,击穿电压大于100V,跨导为236mS/mm,截止频率(fT)达到30GHz,最大振荡频率(fmax)为32GHz,8GHz下在片进行连续波测试,漏端电压为40V时测试得到功率增益4.9dB,输出功率达8W,功率附加效率(PAE)为45%.     

8W AlGaN/GaN HEMT功率器件的研制

报道了基于国产衬底以及国产外延的AlGaN/GaN HEMT X波段功率器件的研究进展.利用国产衬底以及外延材料,优化了器件栅场板的结构,研制成功栅长0.35μm,栅宽为lmm的微波功率器件.该器件输出电流密度达到0.83A/mm,击穿电压大于100V,跨导为236mS/mm,截止频率(fT)达到30GHz,最大振荡频率(fmax)为32GHz,8GHz下在片进行连续波测试,漏端电压为40V时测试得到功率增益4.9dB,输出功率达8W,功率附加效率(PAE)为45%.     

8GHz带有RC稳定网络的AlGaN/GaN HEMTs内匹配功率合成放大器的设计

设计了工作在8GHz的基于AIGaN/GaN HEMTs的内匹配功率合成放大器.输入和输出匹配电路制作在0.381mm厚的氧化铝陶瓷基片上,为了提高整个电路的稳定因子K,在电路输入端增加了片上RC有损网络.在8GHz测出连续波ldB压缩点时的输出功率为PldB=43dBm(20W),线性增益7.3dB,最大PAE为38.1%,合成效率达到70.6%.     

应用于大功率MMIC开关的AlGaN背势垒GaN HEMT

报道了应用于大功率开关的AlGaN背势垒0.25μm GaN HEMT。通过引入AlGaN背势垒,MOCVD淀积在3英寸SiC衬底上的AlGaN/GaN异质结材料缓冲层的击穿电压获得了大幅度的提升,相比于普通GaN缓冲层和掺Fe GaN缓冲层击穿电压提升幅度分别为4倍和2倍。采用具有AlGaN背势垒AlGaN/GaN 外延材料研制的GaN HEMT开关管在源漏间距为2μm、2.5μm、3μm、3.5μm和4μm时,估算得到的关态功率承受能力分别为25.0W、46.2W、64.0W、79.2W和88.4W。基于源漏间距为2.5μm的GaN HEMT开关管设计了DC-12GHz的单刀双掷MMIC开关。该开关采用了反射式串-并-并结构,整个带内插入损耗最大1.0dB、隔离度最小30dB,10GHz下连续波测试得到其功率承受能力达44.1dBm。     

AlGaN/GaN HEMT器件的研制

介绍了AlGaN/GaNHEMT器件的研制及室温下器件特性的测试.漏源欧姆接触采用Ti/Al/Pt/Au ,肖特基结金属为Pt/Au .器件栅长为1μm ,获得的最大跨导为12 0mS/mm ,最大的漏源饱和电流密度为0 95A/mm .     

高频功率AlGaN/GaN HEMT 的栅结构优化

本文研究了栅帽、栅源间距对AlGaN/GaN HEMT性能的影响。基于研究结果得出了优化高频功率AlGaN/GaN HEMT栅结构的方法。缩小栅场板可以有效提高器件的增益、截止频率（ft）、最大震荡频率（fmax）。通过减小栅场板长度,栅长0.35 器件的ft达到了30GHz、fmax达到了80GHz。采用tao型栅（栅帽偏向源侧）或者增加栅金属厚度还可以进一步优化 。缩小栅源的距离可以提高饱和漏电流和击穿电压,从而提高器件的输出功率。     

Ka波段AlGaN/GaN HEMT栅结构仿真研究

为了研究适合Ka波段AlGaN/GaN HEMT的栅结构尺寸,借助二维器件仿真软件Silvaco Atlas,在完善仿真模型的基础上研究了Γ型栅各部分对AlGaN/GaN HEMT特性的影响,包括栅长与短沟道效应的关系、栅与沟道距离对短沟道效应和饱和漏电流的影响,以及栅金属厚度对fmax,栅场板对fT、fmax和内部电场的影响。根据典型器件结构和材料参数的仿真表明,为了提高频率并减轻短沟道效应,栅长应取0.15～0.25μm;减小栅与沟道的距离可略微改善短沟道效应,但会明显降低器件的饱和漏电流,综合考虑栅调制能力、饱和漏电流、短沟道效应三个方面,栅与沟道距离应取10～20nm;为了提高fmax,栅金属厚度应大于0.4μm;缩小栅场板长度可有效提高器件的频率,兼顾Ka波段应用和提高击穿电压,栅场板长度应在0.3～0.4μm左右。仿真得出的器件性能随结构参数的变化趋势以及尺寸数据对于Ka波段AlGaN/GaN HEMT的研究具有参考意义。     

基于AlGaN/GaN HEMT的X波段内匹配功率合成放大器的设计

利用内匹配和功率合成技术设计了X波段AlGaN/GaN HEMT功率合成放大器.电路包含有四个AlGaN/GaN HEMT和制作在Al2O3陶瓷基片上的输入输出匹配电路.在偏置条件VDS=30 V,IDS=700 mA时8 GHz测出连续波饱和输出功率达到Pat=40 dBm(10 W),最大PAE=37.44%,线性增益9 dB.     

Gate-structure optimization for high frequency power AlGaN/GaN HEMTs

The influence of gate-head and gate-source-spacing on the performance of AlGaN/GaN HEMTs was studied.Suggestions are then made to improve the performance of high frequency power AlGaN/GaN HEMTs by optimizing the gate-structure.Reducing the field-plate length can effectively enhance gain,current gain cutoff frequency and maximum frequency of oscillation.By reducing the field-plate length,devices with 0.35 μm gate length have exhibited a current gain cutoff frequency of 30 GHz and a maximum frequency of oscillation of 80 GHz.The maximum frequency of oscillation can be further optimized either by increasing the gate-metal thickness,or by using a t-shape gate (the gate where the gate-head tends to the source side).Reducing the gate-source spacing can enhance the maximum drain-current and breakdown voltage,which is beneficial in enhancing the maximum output power of AlGaN/GaN HEMTs.     

A Ku-band 3.4 W/mm power AlGaN/GaN HEMT on a sapphire substrate

This Daper describes the first domestic Ku-band power AlGaN/GaN HEMT fabricated on a sapphire substrate.The device with a gate width of 0.5 mm and a gate length of 0.35 μm has exhibited an extrinsic current gain cutoff frequency of 20 GHz and an extrinsic maximum frequency of oscillation of 75 GHz.Under V_(DS)=30 V, CW operating conditions at 14 GHz,the device exhibits a linear gain of 10.4 dB and a 3-dB-gain-compressed output power of 1.4 W with a Dower added efficiency of 41%.Under pulse operating conditions,the linear gain is 12.8 dB and the 3-dB-compressed output power is 1.7 W The power density reaches 3.4 W/mm.     

基于蓝宝石衬底的Ku波段3.4W/mm功率AlGaN/GaN HEMT

本文报道了国内第一个基于蓝宝石衬底的ku波段AlGaN/GaN HEMT。器件总栅宽0.5mm,栅长0.35um。漏压30V下器件的ft为20GHz,fmax为75GHz。在漏压30V、连续波测试条件下,器件在14GHz的线性增益为10.4dB,3dB增益压缩的输出功率为1.4W,附加效率41%。在脉冲测试条件下,线性增益12.8dB,3dB增益压缩的输出功率为1.7W,功率密度达到3.4W/mm。     

8GHz带有RC稳定网络的AIGaN/GaN HEMTs内匹配功率合成放大器的设计

设计了工作在8GHz的基于AIGaN/GaN HEMTs的内匹配功率合成放大器.输入和输出匹配电路制作在0.381mm厚的氧化铝陶瓷基片上,为了提高整个电路的稳定因子K,在电路输入端增加了片上RC有损网络.在8GHz测出连续波ldB压缩点时的输出功率为PldB=43dBm(20W),线性增益7.3dB,最大PAE为38.1%,合成效率达到70.6%.     

Hydrogen sensors based on AlGaN/AlN/GaN HEMT

Pt/AlGaN/AlN/GaN high electron mobility transistors (HEMT) were fabricated and characterized for hydrogen sensing. Pt and Ti/Al/Ni/Au metals were evaporated to form the Schottky contact and the ohmic contact, respectively. The sensors can be operated in either the field effect transistor (FET) mode or the Schottky diode mode. Current changes and time dependence of the sensors under the FET and diode modes were compared. When the sensor was operated in the FET mode, the sensor can have larger current change of 8 mA, but its sensitivity is only about 0.2. In the diode mode, the current change was very small under the reverse bias but it increased greatly and gradually saturated at 0.8 mA under the forward bias. The sensor had much higher sensitivity when operated in the diode mode than in the FET mode. The oxygen in the air could accelerate the desorption of the hydrogen and the recovery of the sensor.     

A Ku-band high power density AlGaN/GaN HEMT monolithic power amplifier

A high power density monolithic power amplifier operated at Ku band is presented utilizing a 0.3μm AlGaN/GaN HEMT production process on a 2-inch diameter semi-insulating（SI） 4H-SiC substrate by MOCVD. Over the 12-14 GHz frequency range,the single chip amplifier demonstrates a maximum power of 38 dBm（6.3 W）, a peak power added efficiency（PAE） of 24.2%and linear gain of 6.4 to 7.5 dB under a 10%duty pulse condition when operated at V_ds = 25 V and V_gs = -4 V.At these power levels,the amplifier exhibits a power density in excess of 5 W/mm.     

一种改进的AlGaN/GaN HEMT全局直流模型

对Angelov直流FET模型进行改进,并应用同一遗传算法对改进前后的模型进行全局直流模型参数提取,平均相对误差分别为4.58%和1.8%。将模型计算值与实验数据进行对比,结果表明,改进后的模型能更加准确地描述AlGaN/GaN HEMT源漏电流随栅、漏电压变化的全局直流输出特性,从而为AlGaN/GaN HEMT提供一种准确的全局直流模型和精确的参数提取方法。     

一个Ku波段高功率密度AlGaN/GaN HEMTs单片集成功率放大器

本文报道了一款工作于Ku波段的高功率密度单片集成功率放大器。该放大器采用金属有机化学气相淀积技术在2英寸半绝缘 4H-SiC衬底上生长0.2um AlGaN/GaN HEMTs工艺制作而成。在10%占空比的脉冲偏置Vds=25V,Vgs=-4V条件下,该单片放大器在12-14GHz频率范围内得到最大输出功率38dBm(6.3W),最高PAE 24.2%和线性增益6.4到7.5dB。以这种功率水平而论,该放大器的功率密度超过5W/mm。     

AlGaN/GaN double-channel HEMT

The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported. Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure. The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region. The buffer trap is suggested to be related to the wide region of high transconductance. The RF characteristics are also studied.     

AlGaN/GaN double-channel HEMT

正The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported.Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure.The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region.The buffer trap is suggested to be related to the wide region of high transconductance.The RF characteristics are also studied.