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.     

微波功率器件的滤波器测试电路

在微波电路原理和半导体器件物理的基础上,设计和模拟了三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.模拟和测试结果表明,采用阶梯阻抗滤波器偏置网络的测试电路性能较好,比采用扇形线偏置网络的测试电路具有更宽的带宽.该滤波器偏置电路能够用来在整个C波段,即在4～8GHz内对微波功率器件进行测试.但是,微带叉指耦合电容没有起到取代贴片隔直电容的目的,原因是该结构对参数精度要求高,而PCB制作工艺无法满足这个要求.     

微波功率器件的滤波器测试电路

在微波电路原理和半导体器件物理的基础上,设计和模拟了三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.模拟和测试结果表明,采用阶梯阻抗滤波器偏置网络的测试电路性能较好,比采用扇形线偏置网络的测试电路具有更宽的带宽.该滤波器偏置电路能够用来在整个C波段,即在4～8GHz内对微波功率器件进行测试.但是,微带叉指耦合电容没有起到取代贴片隔直电容的目的,原因是该结构对参数精度要求高,而PCB制作工艺无法满足这个要求.     

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.     

Ku 波段三级功率放大器设计

随着GaAsFET 和MMIC 技术的发展,GaAs 微波功率器件在微波系统中得到了广泛的应用。文中设计了由3个固态功率器件级联的微波功率放大器,通过减宽腔体有效的抑制了因增益过高引起的自激现象,设计了紧凑的MMIC偏置电路以及散热结构。经测试证明,该模块在13.9~14.4GHz 范围内输出功率大于42dBm     

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.     

缺陷接地结构抑制微波器件谐波

对目前应用于微波设计领域的缺陷接地结构(Defected Ground Structure,简称 DGS)进行了介绍,通过电磁场分析软件对非对称DGS进行了分析和优化;根据DGS在某些频率点上的谐振特性,充分利用其带阻特性抑制谐波分量,设计出一种非对称DGS,对工作在S波段2.45 GHz的微波功率器件的二次谐波、三次谐波进行了有效地抑制,在4.9 GHz和7.35 GHz正向传榆系数分别是-14.32 dB和-12.1 dB,仿真和测试结果表明,非对称DGS可以抑制微波器件谐波,有效地提高微波功率器件性能.     

固态微波器件防自激测试夹具研究北大核心CSCD

固态微波器件能够实现微波功率的发射、放大、控制和接收,在移动通讯、雷达等领域有着重要的应用。但是固态微波器件在实际测试中易发生自激振荡,影响其正常工作,甚至会造成永久性的损坏。而良好的测试夹具设计可以有效防止自激振荡现象的发生。因此本文通过分析固态微波器件自激振荡的产生机理,研究制定自激振荡的有效消除措施,提出了固态微波器件防自激测试夹具设计准则,并选取典型GaN微波功率晶体管开展夹具研制加以验证。器件多次重复测试均未发生自激振荡,而且测试结果一致性较好,表明形成的固态微波器件防自激测试夹具设计准则合理可行,能够有助于实现固态微波器件性能参数的精确测试,支撑研制单位的工艺改进和质量提升。     

W波段GaN单片功率放大器研制

报道了W波段GaN三级放大电路的研制结果。采用电子束直写工艺在AlGaN/GaN HEMT外延结构上制备了栅长100nm的"T"型栅结构。器件直流测试最大电流密度为1.3A/mm,最大跨导为430mS/mm;小信号测试外推其fT和fmax分别为90GHz及210GHz。采用该器件设计了三级放大电路,在75~110GHz频段内最大小信号增益为21dB。该单片在90GHz处的最大输出功率可达1.117W,PAE为13%,功率增益为11dB,输出功率密度为2.33 W/mm。     

数字硅MOSFET微波特性的研究

利用国内先进的 0 .6μm数字 Si-MOS工艺 ,设计了射频 MOSFET,并研究了其 DC和微波特性 :I-V曲线、S参数、噪声参数和输出功率。研究发现 ,数字电路用 Si MOSFET的频率响应较高 :频率为 1 GHz时功率增益可达 1 0 d B,2 GHz时为 8d B,4GHz时为 5 d B。 1 .8GHz时 ,1分贝压缩输出功率 1 2 .8d Bm,饱和输出功率可达 1 8d Bm,且最小噪声系数为 3 .5 d B。用提取的参数设计并研制了微波 Si MOSFET低噪声放大器 ,以验证MOS器件的微波性能。此放大器由两级级联而成 ,单电源供电 ,输入输出电容隔直。在频率 1 .7～ 2 .2 GHz的范围内 ,测得放大器增益 1 5± 0 .5 d B,噪声系数 N F<3 .8d B,1分贝压缩输出功率 1 2 d Bm;在频率 1 .5～ 2 .5 GHz的范围内 ,放大器增益大于 1 3 d B。     

Lateral IMPATT diodes

Conventional IMPATT diodes are the highest-power microwave semiconductor devices, but they are difficult to couple light into, challenging to integrate into monolithic circuits, to incorporate a third terminal, or to series combine. The lateral IMPATT diode is proposed as a solution to these problems. This device is planar and features contact and drift regions that are all adjacent to the wafer surface. Two types of fabrication schemes are discussed and pulsed RF power results, up to 17.4 GHz, are demonstrated. This device structure promises to be well suited for microwave, millimeter-wave, and electrooptic integrated circuits in which maximum power is required     

Microwave triode amplifiers from 1 to 2 GHz using molybdenumthin-film-field-emission cathode devices

Experimental results are presented on microwave amplifiers using Molybdenum Thin Film-Field-Emission cathode devices, fabricated at Stanford Research Institute (SRT). A device having 250 tips, operating at 4.8 mA of current with g_m=840 μS is inferred to have an intrinsic power gain of 7 dB at 1.1 GHz. Other results are given for frequencies up to 1.7 GHz. For the first time, device and circuit modeling of sufficient accuracy has been performed that it is possible to confidently deduce the intrinsic performance parameters of the FE devices. The importance of integrated matching circuits for optimum power gain performance is exposed and quantified     

Microwave properties and applications of negative conductance transferred electron devices

The transferred electron effect in epitaxial GaAs has been used to realize a semiconductor device which exhibits a stable negative conductance over a wide range of microwave frequencies and power levels. These devices have been used in conjunction with circulator coupled networks to design high-level wide-band transferred electron amplifiers which have a voltage gain bandwidth product in excess of 10 GHz for frequencies from 4.0 to about 16.0 GHz. Linear gains of 6-12 dB per stage and saturated output power levels in excess of ½ W have been realized. The physical and electrical properties of these devices are described with regard to the achievement of a stable negative conductance. The influence of several parameters (i.e., device temperature, bias voltage, circuit loading, etc.) is discussed with regard to device and circuit stability. Measurements of the terminal admittance of several typical devices as a function of the bias, input power, and frequency have been used to study their microwave properties. The large signal data are used to compute the relationship between the available device power and the magnitude of the negative conductance independent of the test circuit. This same measurement technique can provide a simulation of the performance of any nonlinear negative conductance, without the need for circuit design and load tuning. In addition, an analytical large signal model of the negative conductance has been used to predict the large signal performance of the active device (i.e., gain compression, conversion efficiency, etc.) in both oscillator and amplifier circuits.     

S波段GaN微波功率器件的研制

简要介绍了第三代新型半导体材料GaN的特点和优势,基于Agilent ADS微波仿真软件设计并实现了一款工作于S波段基于GaN的高效超宽带微波功率器件。测试结果表明,该器件适用于2.7～3.5GHz的超宽带,连续波和脉冲制式均可工作,在饱和状态下,输出功率大于15W,增益达到13dB,漏极效率超过45%,并在管壳内部实现了匹配和偏置电路,对GaN MOSFET微波功率器件小型化、超宽带、高增益和高效率的优异性能得以验证和实现。     

Ku波段GaAs单片功率放大器

基于GaAs PHEMT在微波领域的卓越性能,设计并实现了两款Ku波段GaAs单片功率放大器。简述了GaAs PHEMT器件的工作原理,并抽取了精准的EEHEMT模型,通过独特的设计方法并结合相应的仿真软件设计了两款Ku波段单片功率放大器。经过精准测试,两款电路呈现的性能如下:在13～14GHz频带内,其中第一款电路的饱和输出功率Po>38dBm(脉宽100μs,占空比10%),功率增益GP>20dB,典型功率附加效率PAE>28%;第二款电路的饱和输出功率Po>40dBm(脉宽100μs,占空比10%),功率增益GP>19dB,典型功率附加效率PAE>28%。结果表明,基于PHEMT的GaAs单片功率放大器在Ku波段可以实现优良的性能。     

Ku波段30W脉冲微波功率放大器模块

报道了Ku波段30W脉冲微波功率放大器模块的研制. 模块的微波放大链路由5级固态功率器件级联构成,采用新颖的双层腔体结构,消除了低频电路与高频电路的互扰.针对Ku波段内匹配MESFET设计了双段式偏置电路,有效抑制了低频振荡. 在脉冲重复频率3kHz,占空比10%下,模块在13.5~14.0GHz工作频段内的功率增益GP≥44dB,输出脉冲峰值功率Ppk≥30W,总效率η≥13% (A类放大状态）.     

Waveguide/resonant-disc circuits for millimetre-wave devices

Bias circuits using resonant discs have been employed for millimetre-wave transferred-electron (TE) diodes operating at their second or third harmonic frequencies in the V (50?75 GHz) and W (75?110 GHz) bands. It is shown that this type of circuit exhibits resonances at frequencies in the lower millimetre-wave range, corresponding to the fundamental oscillation frequency of diodes typically used. In addition, the circuit provides efficient coupling to the waveguide circuit at the higher (harmonic) operating frequency. By tuning the fundamental oscillation frequency of a number of resonant discs, the power-frequency spectrum of the TE device can be determined, which is demonstrated for a device with its maximum third-harmonic power output at 94 GHz.