High-power monolithic AlGaN/GaN HEMT oscillator

A monolithic X-band oscillator based on an AlGaN/GaN high electron mobility transistor (HEMT) has been designed, fabricated, and characterized. A common-gate HEMT with 1.5 mm of gate width in conjunction with inductive feedback is used to generate negative resistance. A high Q resonator is implemented with a short-circuit low-loss coplanar waveguide transmission line. The oscillator delivers 1.7 W at 9.556 GHz into 50-/spl Omega/ load when biased at V/sub ds/=30 V and V/sub gs/=-5 V, with dc-to-RF efficiency of 16%. Phase noise was estimated to be -87 dBc/Hz at 100-kHz offset. Low-frequency noise, pushing and pulling figures, and time-domain characterization have been performed. Experimental results show great promise for AlGaN/GaN HEMT MMIC technology to be used in future high-power microwave source applications.     

An 8 GHz high power AlGaN/GaN HEMT VCO

A high power X-band hybrid microwave integrated voltage controlled oscillator(VCO) based on Al-GaN /GaN HEMT is presented.The oscillator design utilizes a common-gate negative resistance structure with open and short-circuit stub microstrip lines as the main resonator for a high Q factor.The VCO operating at 20 V drain bias and-1.9 V gate bias exhibits an output power of 28 dBm at the center frequency of 8.15 GHz with an efficiency of 21%.Phase noise is estimated to be -85 dBc/Hz at 100 kHz offset and -1...     

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。     

High-power monolithic AlGaN/GaN HEMT switch for X-band applications

The design, fabrication and test of X-band high-power monolithic SPDT switches in microstrip GaN technology are presented. Such switches have demonstrated state-of-the-art performance: they exhibit 1 dB on-state insertion loss and better than 37 dB isolation. Power- handling measurements have shown that no compression phenomenon occurs with an input power equal to 39.5 dBm at 10 GHz.     

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。     

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.     

A V-Band Monolithic AlGaN/GaN VCO

A V-band push-push GaN monolithic microwave integrated circuit voltage controlled oscillator (VCO) has been realized based on a 0.2 mum T-gate AlGaN/GaN high electron mobility transistor technology with an fT ~ 65 GHz. The GaN VCO delivered an output power of +11 dBm at 53 GHz with an estimated phase noise of -97 dBc/Hz at 1 MHz offset based on on-wafer measurement. To the best of our knowledge, this is the highest frequency VCO ever reported for GaN technology with a high output power at V-band, without using any buffer amplifier. This work demonstrates the potential of applying GaN technology to millimeter wave band, high power, and low phase noise frequency sources applications.     

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.     

A high-performance enhancement-mode AlGaN/GaN HEMT

An enhancement-mode AlGaN/GaN HEMT with a threshold voltage of 0.35 V was fabricated by fluorine plasma treatment.The enhancement-mode device demonstrates high-performance DC characteristics with a saturation current density of 667 mA/mm at a gate bias of 4 V and a peak transconductance of 201 mS/mm at a gate bias of 0.8 V.The current-gain cut-off frequency and the maximum oscillation frequency of the enhancement-mode device with a gate length of μm are 10.3 GHz and 12.5 GHz,respectively,which is comparable with the depletion-mode device.A numerical simulation supported by SIMS results was employed to give a reasonable explanation that the fluorine ions act as an acceptor trap center in the barrier layer.     

高性能的增强型AlGaN/GaN HEMT

采用氟离子处理的方法实现了阈值电压0.35V的增强型AlGaN/GaN HEMT 器件。该器件展示了高性能直流特性,最大饱和电流 667mA/mm,器件的峰值跨导达到203ms/mm。 1μm栅长电流增益截止频率和最大振荡截止频率分别为10.3GHz和12.5GHz,并且小信号特性在器件氟离子处理后并没有出现衰退。最后,采用SIMS的实验结果辅助进行了数值仿真,对氟离子在势垒层中起受主缺陷的理论给出了合理的解释。     

AlGaN/GaN HEMT器件的研制

介绍了AlGaN/GaN HEMT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120mS/mm,最大的漏源饱和电流密度为0.95A/mm.     

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 .     

Copper gate AlGaN/GaN HEMT with low gate leakage current

Copper (Cu) gate AlGaN/GaN high electron mobility transistors (HEMTs) with low gate leakage current were demonstrated. For comparison, nickel/gold (Ni/Au) gate devices were also fabricated with the same process conditions except the gate metals. Comparable extrinsic transconductance was obtained for the two kinds of devices. At gate voltage of -15 V, typical gate leakage currents are found to be as low as 3.5/spl times/10/sup -8/ A for a Cu-gate device with gate length of 2 /spl mu/m and width of 50 /spl mu/m, which is much lower than that of Ni/Au-gate device. No adhesion problem occurred during these experiments. Gate resistance of Cu-gate is found to be about 60% as that of NiAu. The Schottky barrier height of Cu on n-GaN is 0.18 eV higher than that of Ni/Au obtained from Schottky diode experiments. No Cu diffusion was found at the Cu and AlGaN interface by secondary ion mass spectrometry determination. These results indicate that copper is a promising candidate as gate metallization for high-performance power AlGaN/GaN HEMT.     

A 108-GHz InP-HBT monolithic push-push VCO with low phase noise andwide tuning bandwidth

This paper reports on what is believed to be the highest frequency bipolar voltage-controlled oscillator (VCO) monolithic microwave integrated circuit (MMIC) so far reported. The W-band VCO is based on a push-push oscillator topology, which employs InP HBT technology with peak f_T's and f_max's of 75 and 200 GHz, respectively. The W-band VCO produces a maximum oscillating frequency of 108 GHz and delivers an output power of +0.92 dBm into 50 Ω. The VCO also obtains a tuning bandwidth of 2.73 GHz or 2.6% using a monolithic varactor. A phase noise of -88 dBc/Hz and -109 dBc/Hz is achieved at 1- and 10-MHz offsets, respectively, and is believed to be the lowest phase noise reported for a monolithic W-band VCO. The push-push VCO design approach demonstrated in this work enables higher VCO frequency operation, lower noise performance, and smaller size, which is attractive for millimeter-wave frequency source applications     

Q-band high-efficiency monolithic HEMT power prematch structures

Monolithic Q-band high-efficiency prematch structures using 0.15 μm double-heterostructure pseudomorphic AlGaAs-InGaAs-GaAs HEMTs have been designed, fabricated and evaluated. The structures include a 400 μm and an 800 μm gate-width unit, demonstrating power-added efficiency of 41.6% and 37%, respectively, which represents state-of-the-art efficiency performance at this frequency. These building-blocks can be used easily to construct high-power, high-efficiency amplifiers. The circuit design, output power and efficiency performance of the prematch structures are also presented     

X-波段AlGaN/GaN HEMT 功率MMIC

AlGaN/GaN高电子迁移率晶体管(HEMT)以其高输出功率密度、高电压工作和易于宽带匹配优势将成为下一代高频固态微波功率器件.     

非掺杂AlGaN/GaN微波功率HEMT

报道了研制的AlGaN/GaN微波功率HEMT,该器件采用以蓝宝石为衬底的非掺杂AlGaN/GaN异质结构,器件工艺采用了Ti/Al/Ni/Au欧姆接触和Ni/Au肖特基势垒接触以及SiN介质进行器件的钝化.研制的200μm栅宽T型布局AlGaN/GaN HEMT在1.8GHz,Vds=30V时输出功率为28.93dBm,输出功率密度达到3.9W/mm,功率增益为15.59dB,功率附加效率(PAE)为48.3%.在6.2GHz,Vds=25V时该器件输出功率为27.06dBm,输出功率密度为2.5W/mm,功率增益为10.24dB,PAE为35.2%.     

非掺杂AlGaN/GaN微波功率HEMT

报道了研制的Al Ga N / Ga N微波功率HEMT,该器件采用以蓝宝石为衬底的非掺杂Al Ga N/ Ga N异质结构,器件工艺采用了Ti/ Al/ Ni/ Au欧姆接触和Ni/ Au肖特基势垒接触以及Si N介质进行器件的钝化.研制的2 0 0μm栅宽T型布局Al Ga N / Ga N HEMT在1.8GHz,Vds=30 V时输出功率为2 8.93d Bm,输出功率密度达到3.9W/mm ,功率增益为15 .5 9d B,功率附加效率(PAE)为4 8.3% .在6 .2 GHz,Vds=2 5 V时该器件输出功率为2 7.0 6 d Bm ,输出功率密度为2 .5 W/ mm ,功率增益为10 .2 4 d B,PAE为35 .2 % .     

一种新的AlGaN/GaN HEMT半经验直流特性模型

在EEHEMT1模型的基础上给出一种新的A1GaN/GaN HEMT半经验直流特性模型,考虑了栅源电压对膝点电压的影响,得到描述AlGaN/GaN HEMT器件I-Ⅴ特性的方程.此模型可以应用于蓝宝石和SiC两种不同衬底AlGaN/GaN HEMT器件的I-Ⅴ特性模拟.仿真结果和实验测量结果拟合误差小于3%.