SiC MESFET微波功率器件的研制

利用本实验室生长的4H-SiC外延材料开展了SiC微波功率器件的研究．通过对欧姆接触和干法刻槽工艺的优化,研制出高性能的SiCMESFET．利用1mm栅宽SiC MESFET制成的微波功率放大器在2GHz64V工作时,连续波输出功率达4．09W,功率增益为9．3dB,PAE为31．3％．文中还给出了SiC功率放大器在微波大信号工作时的稳定性的初步测试结果．     

SiC MESFET微波功率测试技术

对SiC MESFET的微波测试技术进行了分析,并针对这一采用第三代半导体材料研制的器件,结合硅微波双极功率晶体管和GaAs MESFET的测试技术,建立了SiC MESFET的微波测试系统,完成了2GHz工作频率下瓦级功率输出SiC MESFET的测试,功率增益大于6dB,器件的fT为6.7GHz,fmax达25GHz.     

SiC MESFET微波功率测试技术

对SiC MESFET的微波测试技术进行了分析,并针对这一采用第三代半导体材料研制的器件,结合硅微波双极功率晶体管和GaAs MESFET的测试技术,建立了SiC MESFET的微波测试系统,完成了2GHz工作频率下瓦级功率输出SiC MESFET的测试,功率增益大于6dB,器件的fT为6.7GHz,fmax达25GHz.     

SiC MESFET微波功率测试技术

对SiC MESFET的微波测试技术进行了分析，并针对这一采用第三代半导体材料研制的器件，结合硅微波双极功率晶体管和GaAs MESFET的测试技术，建立了SiC MESFET的微波测试系统，完成了2GHz工作频率下瓦级功率输出SiC MESFET的测试，功率增益大于6dB，器件的fT为6.7GHz, fmax达25GHz.     

导通和半绝缘衬底上的SiC MESFET

分别在导通和半绝缘4H-SiC衬底上外延生长了MESFET结构并制成器件.两种衬底上的SiC MESFET具有类似的直流特性,饱和电流为350mA/mm,最大跨导为25～30mS/mm,击穿电压大于120V.导通衬底上的SiC MESFET在2GHz 50V工作时饱和输出功率为1.75W;在相同条件下半绝缘衬底的SiC MESFET饱和输出功率为3.38W,64V工作时最大输出功率超过4W.缓冲层参数的不同是造成微波性能差异的主要原因.     

导通和半绝缘衬底上的SiC MESFET

分别在导通和半绝缘4H-SiC衬底上外延生长了MESFET结构并制成器件.两种衬底上的SiC MESFET具有类似的直流特性,饱和电流为350mA/mm,最大跨导为25～30mS/mm,击穿电压大于120V.导通衬底上的SiC MESFET在2GHz 50V工作时饱和输出功率为1.75W;在相同条件下半绝缘衬底的SiC MESFET饱和输出功率为3.38W,64V工作时最大输出功率超过4W.缓冲层参数的不同是造成微波性能差异的主要原因.     

微波大功率SiC MESFET及MMIC

利用本实验室生长的4H-SiC外延材料开展了SiC MESFET和MMIC的工艺技术研究.研制的SiC MESFET采用栅场板结构,显示出优异的脉冲功率特性,20 mm栅宽器件在2 GHz脉冲输出功率达100 W.将四个20 mm栅宽的SiC MESFET芯片通过内匹配技术进行功率合成,合成器件的脉冲功率超过320 W,增益8.6 dB.在实现SiC衬底减薄和通孔技术的基础上,设计并研制了国内第一片SiC微波功率MMIC,在2～4 GHz频带内小信号增益大于10 dB,脉冲输出功率最大超过10 W.     

SiC宽禁带功率放大器的设计与实践

介绍了SiC宽禁带功率器件的特性,与Si功率器件相比,该器件在输出功率、功率密度、工作频率、工作带宽、环境适应性、抗辐射能力等方面有卓越的性能.利用SiC宽禁带功率器件设计制作了L波段100W功率放大器.对SiC宽禁带功率放大器进行性能测试和环境实验,分析了SiC宽禁带功率器件的性能特点和优势.SiC宽禁带功率器件有利于提高功率放大器的工作带宽,改善功率放大器的环境适应性.     

S波段280 W SiC内匹配脉冲功率管

现代雷达和通讯系统要求不断地提高微波功率器件的功率、效率以及带宽.SiC MESFET具有高功率密度、高工作电压等优势,成为目前国际上重点研究的微波功率器件之一.     

S波段大功率SiC MESFET的设计与工艺制作

针对SiC功率金属半导体场效应晶体管如何在实现高性能的同时保证器件长期稳定的工作,从金属半导体接触、器件制造过程中的台阶控制、氧化与钝化层的设计及器件背面金属化实现等方面进行了分析;并结合具体工艺,对比给出了部分实验结果。从测试数据看,研制的微波SiC MESFET器件性能由研制初期在S波段瓦级左右的功率输出及较低的功率增益和功率附加效率,达到了在实现大功率输出的条件下,比Si器件高的功率增益和30%以上的功率附加效率,初步体现了SiC MESFET微波功率器件的优势,器件的稳定性也得到了提升,为器件性能和可靠性的进一步提升奠定了设计和工艺基础。     

SiC宽带功率放大器模块设计分析

功率放大器是射频前端中的关键部件,宽带是目前功率放大器的主要发展趋势。基于碳化硅(SiC)宽禁带功率器件,利用ADS仿真软件,依据宽带功率放大器的各项指标进行电路的设计、优化和仿真,制作了500~2 000 MHz波段宽带功率放大器,并对放大器进行了性能测试和环境实验。测试结果表明利用该方法设计宽带功率放大器是可行的,SiC宽禁带功率器件具有较宽的工作带宽。     

AlGaN/GaN HEMTs on SiC for high power broadband applications up to 40 GHz

An overview of properties and recent achievements for AlGaN/GaN high electron mobility transistors (HEMT) on semi-insulating SiC substrate is given towards high power and broadband applications up to a frequency of 40 GHz. Starting from epitaxial growth and process technology we present state-of-the-art power results obtained at the Fraunhofer Institute (IAF) from AlGaN/GaN HEMTs on SiC. Further, a one-stage 16 GHz MMIC power amplifier circuit with 1.6 W output power is presented. This result represents the first AlGaN/GaN MMIC on SiC fabricated in Europe.     

An X-band four-way combined GaN solid-state power amplifier

An X-band four-way combined GaN solid-state power amplifier module is fabricated based on a self-developed AlGaN/GaN HEMT with 2.5-mm gate width technology on SiC substrate. The module consists of an Al-GaN/GaN HEMT, Wilkinson power hybrids, a DC-bias circuit and microstrip matching circuits. For the stability of the amplifier module, special RC networks at the input and output, a resistor between the DC power supply and a transistor gate at the input and 3λ/4 Wilkinson power hybrids are used for the cancellation of low frequency self-oscillation and crosstalk of each amplifier. Under V_(ds)= 27 V, V_(gs) = -4.0 V, CW operating conditions at 8 GHz, the amplifier module exhibits a line gain of 5 dB with a power added efficiency of 17.9%, and an output power of 42.93 dBm; the power gain compression is 2 dB. For a four-way combined solid-state amplifier, the power combining efficiency is 67.5%. It is concluded that the reduction in combining efficiency results from the non-identical GaN HMET, the loss of the hybrid coupler and the circuit fabricating errors of each one-way amplifier.     

Design of wideband hybrid silicon carbide single-stage power amplifier

RF wideband power amplifiers are desirable as they will reduce equipment, power consumption and operating cost for the RF communication infrastructure. For decades, the realization of single-stage broadband power amplifier has posed a significant challenge due to the electrical and thermal limitations of GaAs transistor technology. Silicon carbide (SiC) MESFET technology is a strong contender for such applications due to its superior properties. In particular, its high impedance reduces mismatch commonly encountered in such power amplifier.In this work, design of wideband hybrid single-stage power amplifier using a commercial 4H-SiC MESFET CRF24010 from Cree Inc is presented. The amplifier has been designed and fabricated for operating frequencies 650-1800 MHz, which is equivalent to more than 90% bandwidth, compared to only 3-4% bandwidth achievable using GaAs technology.     

基于大信号模型的L波段400W高效GaN功率放大器设计

文章阐述了用精确的GaN Angelov模型设计了一款L波段400W内匹配率放大器.选用SiC衬底的GaN器件是为了获得大功率输出以及高效率性能.为了精确设计放大器,采用脉冲I-V测试和多偏置的S参数测试建立起高压GaN大信号模型.采用模型设计的GaN放大器输入输出电路集成在17.4mm×24mm的封装管壳里.最终采用单枚55mm栅宽GaN管芯设计的放大器在48V漏压,100μs脉宽,10%占空比偏置下在1.2~1.4GHz输出功率大于400W,功率增益大于15dB,最高功率附加效率达到81.3%,这是国内L波段400W微波功率放大器的最高效率报道,验证了模型的准确度,实现了极好的电路性能.     

A Wideband Power Amplifier MMIC Utilizing GaN on SiC HEMT Technology

The design and performance of a wideband power amplifier MMIC suitable for electronic warfare (EW) systems and other wide bandwidth applications is presented. The amplifier utilizes dual field plate 0.25- mum GaN on SiC device technology integrated into the three metal interconnect (3 MI) process flow. Experimental results for the MMIC at 30 V power supply operation demonstrate greater than 10 dB of small signal gain, 9 W to 15 W saturated output power and 20% to 38% peak power-added efficiency over a 1.5 GHz to 17 GHz bandwidth.     

具有平坦增益的X波段GaN单片功率放大器

A flat gain two-stage MMIC power amplifier with a 2.8 GHz bandwidth is successfully developed for X band frequency application based on a fully integrated micro-strip Al Ga N/Ga N HEMT technology on a semiinsulating Si C substrate. Designed with a binary-cluster matching structure integrated with RC networks and LRC networks, the developed power MMIC gets a very flat small signal gain of 15 d B with a gain ripple of 0.35 d B over 9.1–11.9 GHz at the drain bias of 20 V. These RC networks are very easy to improve the stability of used Ga N HEMTs with tolerance to the MMIC technology. Inside the frequency range of 9–11.2 GHz where the measurement system calibrated, the amplifier delivers a pulsed output power of 39 d Bm and an associated power added efficiency of about 20% at 28 V without saturation, as the available RF power is limited.     

6‐GHz‐to‐18‐GHz AlGaN/GaN Cascaded Nonuniform Distributed Power Amplifier MMIC Using Load Modulation of Increased Series Gate Capacitance

A 6‐GHz‐to‐18‐GHz monolithic nonuniform distributed power amplifier has been designed using the load modulation of increased series gate capacitance. This amplifier was implemented using a 0.25‐μm AlGaN/GaN HEMT process on a SiC substrate. With the proposed load modulation, we enhanced the amplifier's simulated performance by 4.8 dB in output power, and by 13.1% in power‐added efficiency (PAE) at the upper limit of the bandwidth, compared with an amplifier with uniform gate coupling capacitors. Under the pulse‐mode condition of a 100‐μs pulse period and a 10% duty cycle, the fabricated power amplifier showed a saturated output power of 39.5 dBm (9 W) to 40.4 dBm (11 W) with an associated PAE of 17% to 22%, and input/output return losses of more than 10 dB within 6 GHz to 18 GHz.     

Broadband GaN HEMT push-pull microwave power amplifier

We report a broadband, linear, push-pull amplifier that utilizes GaN-based HEMTs grown on SiC substrates. The high power density capabilities of these devices can be enhanced by the high efficiency achievable with push-pull operation. Good amplifier performance is facilitated by use of a new low-loss balun that is implemented with three symmetric coupled lines and which showed insertion loss of less than 0.5 dB per balun. The bias was injected through the baluns, thereby simplifying the amplifier design and reducing loss associated with dc decoupling capacitors. Using two 1.5 mm HEMTs with 0.35-μm gate length, a push-pull amplifier produced a small-signal gain of 8 dB at 5 GH2, a 3 dB bandwidth of 3.5-10.5 GHz, and a PAE of 25%