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1.
正We studied the performance of AlGaN/GaN double heterojunction high electron mobility transistors (DH-HEMTs) with an AlGaN buffer layer,which leads to a higher potential barrier at the backside of the twodimensional electron gas channel and better carrier confinement.This,remarkably,reduces the drain leakage current and improves the device breakdown voltage.The breakdown voltage of AlGaN/GaN double heterojunction HEMTs (~ 100 V) was significantly improved compared to that of conventional AlGaN/GaN HEMTs(~50 V) for the device with gate dimensions of 0.5 x 100μm and a gate-drain distance of 1μm.The DH-HEMTs also demonstrated a maximum output power of 7.78 W/mm,a maximum power-added efficiency of 62.3%and a linear gain of 23 dB at the drain supply voltage of 35 V at 4 GHz.  相似文献   

2.
正AlGaN/GaN HEMTs with 0.2μm V-gate recesses were developed.The 0.2μm recess lengths were shrunk from the 0.6μm designed gate footprint length after isotropic SiN deposition and anisotropic recessed gate dry etching.The AlGaN/GaN HEMTs with 0.2μm V-gate recesses on sapphire substrates exhibited a current gain cutoff frequency f_t of 35 GHz and a maximum frequency of oscillation f_(max) of 60 GHz.At 10 GHz frequency and 20 V drain bias,the V-gate recess devices exhibited an output power density of 4.44 W/mm with the associated power added efficiency as high as 49%.  相似文献   

3.
SiN dielectrically-defined 0.15μm field plated GaN HEMTs for millimeter-wave application have been presented.The AlGaN/GaN hetero-structure epitaxial material for HEMTs fabrication was grown on a 3-inch SiC substrate with an Fe doped GaN buffer layer by metal-organic chemical deposition.Electron beam lithography was used to define both the gate footprint and the cap of the gate with an integrated field plate.Gate recessing was performed to control the threshold voltage of the devices.The fabricated GaN HEMTs exhibited a unit current gain cut-off frequency of 39 GHz and a maximum frequency of oscillation of 63 GHz.Load-pull measurements carried out at 35 GHz showed a power density of 4 W/mm with associated power gain and power added efficiency of 5.3 dB and 35%,respectively,for a 0.15 mm gate width device operated at a 24 V drain bias.The developed 0.15μm gate length GaN HEMT technology is suitable for Ka band applications and is ready for millimeter-wave power MMICs development.  相似文献   

4.
We report the DC and RF characteristics of AlN/GaN high electron mobility transistors(HEMTs) with the gate length of 100 nm on sapphire substrates. The device exhibits a maximum drain current density of 1.29 A/mm and a peak transconductance of 440 m S/mm. A current gain cutoff frequency and a maximum oscillation frequency of 119 GHz and 155 GHz have been obtained, respectively. Furthermore, the large signal load pull characteristics of the AlN/GaN HEMTs were measured at 29 GHz. An output power density of 429 m W/mm has been demonstrated at a drain bias of 10 V. To the authors’ best knowledge, this is the earliest demonstration of power density at the Ka band for Al N/Ga N HEMTs in the domestic, and also a high frequency of load-pull measurements for Al N/Ga N HEMTs.  相似文献   

5.
We report high performance InAlN/GaN HEMTs grown on sapphire substrates.The lattice-matched InAlN/GaN HEMT sample showed a high 2DEG mobility of 1210 cm2/(V·s) under a sheet density of 2.6×1013 cm-2.Large signal load-pull measurements for a(2×100μm)×0.25μm device have been conducted with a drain voltage of 24 V at 10 GHz.The presented results confirm the high performances reachable by InAlN-based technology with an output power density of 4.69 W/mm,a linear gain of 11.8 dB and a peak power-added efficiency of 48%.This is the first report of high performance InAlN/GaN HEMTs in mainland China.  相似文献   

6.
The fabrication of enhancement-mode AlGaN/GaN HEMTs by fluorine plasma treatment on sapphire substrates is reported. A new method is used to fabricate devices with different fluorine plasma RF power treatments on one wafer to avoid differences between different wafers. The plasma-treated gate regions of devices treated with different fluorine plasma RF powers were separately opened by a step-and-repeat system. The properties of these devices are compared and analyzed. The devices with 150 W fluorine plasma treatment power and with 0.6 μm gate-length exhibited a threshold voltage of 0.57 V, a maximum drain current of 501 mA/mm, a maximum transconductance of 210 mS/mm, a current gain cutoff frequency of 19.4 GHz and a maximum oscillation frequency of 26 GHz. An excessive fluorine plasma treatment power of 250 W results in a small maximum drain current, which can be attributed to the implantation of fluorine plasma in the channel.  相似文献   

7.
刘波 《半导体学报》2013,34(4):044006-4
We report the DC and RF performance of InAlN/GaN high-electron mobility transistors with AlGaN back barrier grown on SiC substrates.These presented results confirm the high performance that is reachable by InAlN-based technology.The InAlN/GaN HEMT sample showed a high 2DEG mobility of 1550 cm2/(V·s) at a 2DEG density of 1.7×1013 cm-2.DC and RF measurements were performed on the unpassivated device with 0.2μm "T" gate.The maximum drain current density at VGS = 2 V is close to 1.05 A/mm in a reproducible way. The reduction in gate leakage current helps to increase the frequency performance of AIGaN back barrier devices. The power gain cut-off frequency of a transistor with an AIGaN back barrier is 105 GHz,which is much higher than that of the device without an AIGaN back barrier at the same gate length.These results indicate InAlN/GaN HEMT is a promising candidate for millimeter-wave application.  相似文献   

8.
We report high performance InAlN/GaN HEMTs grown on sapphire substrates. The lattice-matched InAlN/GaN HEMT sample showed a high 2DEG mobility of 1210 cm2/(V·s) under a sheet density of 2.6 × 1013 cm-2. Large signal load-pull measurements for a (2 × 100 μm) × 0.25 μm device have been conducted with a drain voltage of 24 V at 10 GHz. The presented results confirm the high performances reachable by InAlN-based technology with an output power density of 4.69 W/mm, a linear gain of 11.8 dB and a peak power-added efficiency of 48%. This is the first report of high performance InAlN/GaN HEMTs in mainland China.  相似文献   

9.
RF-MBE Grown AlGaN/GaN HEMT Structure with High Al Content   总被引:5,自引:5,他引:0  
A Si doped AlGaN/GaN HEMT structure with high Al content (x=43%) in the barrier layer is grown on sapphire substrate by RF-MBE.The structural and electrical properties of the heterostructure are investigated by the triple axis Xray diffraction and Van der PauwHall measurement,respectively.The observed prominent Bragg peaks of the GaN and AlGaN and the Hall results show that the structure is of high quality with smooth interface.The high 2DEG mobility in excess of 1260cm2/(V·s) is achieved with an electron density of 1.429e13cm-2 at 297K,corresponding to a sheet-densitymobility product of 1.8e16V-1·s-1.Devices based on the structure are fabricated and characterized.Better DC characteristics,maximum drain current of 1.0A/mm and extrinsic transconductance of 218mS/mm are obtained when compared with HEMTs fabricated using structures with lower Al mole fraction in the AlGaN barrier layer.The results suggest that the high Al content in the AlGaN barrier layer is promising in improving material electrical properties and device performance.  相似文献   

10.
正We report a high power Ku band internally matched power amplifier(IMPA) with high power added efficiency(PAE) using 0.3μm AlGaN/GaN high electron mobility transistors(HEMTs) on 6H-SiC substrate.The internal matching circuit is designed to achieve high power output for the developed devices with a gate width of 4 mm.To improve the bandwidth of the amplifier,a T type pre-matching network is used at the input and output circuits,respectively.After optimization by a three-dimensional electromagnetic(3D-EM) simulator,the amplifier demonstrates a maximum output power of 42.5 dBm(17.8 W),PAE of 30%to 36.4%and linear gain of 7 to 9.3 dB over 13.8-14.3 GHz under a 10%duty cycle pulse condition when operated at V_(ds) = 30 V and V_(gs)=—4 V.At such a power level and PAE,the amplifier exhibits a power density of 4.45 W/mm.  相似文献   

11.
在大型扩声系统中,功放机是经常损坏的设备,而且损坏的情况大部分是末级功率放大器件的烧坏。经过对正常工作的功放机仔细观察发现,末级并联使用的同型号大功率三极管(场效应管)工作时,往往有的温度高,有的温度低。其中造成上述情况的主要原因是并联使用的大功率三极管(场效应管)在装机时由于筛选时的疏忽或长期运行造成特性参数差异,引起负荷不均匀。负荷大者,工作电流大,发热也较大,容易先坏。负荷小者,工作电流小,发热也较小。但发热大的损坏后,发热小的也不堪重负,短时间内也会烧毁。因此,延长功放机使用寿命,末级功…  相似文献   

12.
功率因数是开关电源设计的关键指标,提高功率因数是开关电源发展中一直重视的技术问题.这里设计的高功率因数开关电源应用PFC控制方式,引进TI公司新推出的UCC28019芯片,明显提高了功率因数.该电源由AC/DC变换电路、DC/IX;变换电路、PFC控制电路、功率因数检测电路、数字设定及测量显示电路、保护电路等6部分组成.其中,AC/DC变换电路采用桥式不控整流方式,DC/DC变换电路采用Boost拓扑结构,可实现30~36 V可调输出,并利用MSP430F247单片机实现数字设定、测量显示及功率因素检测等功能.该电源的主要优点是:功能直观、稳定性好、功率因数大幅度提高.  相似文献   

13.
将改进后的PBIL算法运用到含风力发电机组的IEEE30节点系统的无功优化计算中,并对多次独立计算的结果做了统计和分析,与采用标准的遗传算法(SGA)的计算结果的比较,请明该算法在此类无功优化问题中有效性和可靠性。  相似文献   

14.
《电子设计技术》2001,(4):84-87
输出300mA的低压差线性稳压器 Maxim公司的MAX8887/MAX888为低压差线性稳压器,输入电压范围:+2.5V至+5.5V,连继输出300mA电流(脉冲电流达500mA),MAX8887的噪声很低,而MAX8888具有开漏输出的“电源正常”指示器。它们在输出电流为200mA时压差为  相似文献   

15.
数字电源管理IC是个新概念,它融合了模拟管理与数字转换,提高了电源效率.近日,美国Ziler Labs公司来华介绍了数字电源及Zilker的新产品.  相似文献   

16.
Prasad Subramaniam 《电子设计技术》2010,17(8):46-46,48,50,52,54
为了实现目前的功率管理目标,需要采取一种全面的功率管理方法,下至晶体管,上至全芯片技术,悉数包含在内。  相似文献   

17.
通过开关电源待机功耗改进方法的研究来提高产品的节能能力。  相似文献   

18.
低功率高压电源的模块化设计   总被引:1,自引:0,他引:1  
随着现代雷达技术的飞速发展,以及现代雷达对缩短研制周期、提高可维护性和可靠性的要求,小型化、模块化已经成为现代雷达技术发展的方向。作为雷达发射机关键部分的高压电源必须进行模块化设计,提高效率和可维护性以及可靠性,减小体积和重量,以适应现代雷达的要求,本文重点介绍低功率高压电源的模块化设计。  相似文献   

19.
构建有源功率因数校正(APFC)的高功率因数直流电源。该系统采用TI公司专用APFC整流控制芯片UCC28019作为控制核心,构成电压外环和电流内环的双环控制。其中内环电流环作用是使网侧交流输入电流跟踪电网电压的波形与相位;外环电压环为输出直流电压控制环。外环电压调节器的输出控制内环电流调节器的增益,使输出直流电压稳定。系统采用ATmega16单片机进行监控,完成输出电压的可调以及输入功率因数、输出电压、输出电流等的实时测量与显示和输出过流保护等功能。实测表明,系统性能指标完全达到或超过设计要求。  相似文献   

20.
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