太赫兹InP基InAlAs/InGaAs PHEMTs的研制

研制了一种T型栅长为90 nm的InP基In0.52Al0.48As/In0.65Ga0.35As赝配高电子迁移率晶体管(PHEMTs).该器件的总栅宽为2×25 μm,展现了极好的DC直流和RF射频特性,其最大饱和电流密度和最大有效跨导分别为894 mA/mm和1640 mS/mm.采用LRM+ (Line-Reflect-Reflect -Match)校准方法实现系统在1~110 GHz全频段内一次性校准,减小了传统的分段测试多次校准带来的误差, 且测试数据的连续性较好.在国内完成了器件的1~110 GHz全频段在片测试,基于1~110 GHz在片测试的S参数外推获得的截止频率ft和最大振荡频率fmax分别为252 GHz和394 GHz.与传统的测试到40 GHz外推相比,本文外推获得的fmax更加准确.这些结果的获得是由于栅长的缩短,寄生效应的减小以及1~110 GHz全频段在片测试的实现.器件的欧姆接触电阻率减小为0.035 Ω·mm.     

太赫兹InP基InAlAs/InGaAs PHEMTs的研制（英文）

研制了一种T型栅长为90 nm的InP基In_(0.52)Al_(0.48)As/In_(0.65)Ga_(0.35)As赝配高电子迁移率晶体管(PHEMTs).该器件的总栅宽为2×25μm,展现了极好的DC直流和RF射频特性,其最大饱和电流密度和最大有效跨导分别为894 m A/mm和1 640 m S/mm.采用LRM+(Line-Reflect-Reflect-Match)校准方法实现系统在1~110 GHz全频段内一次性校准,减小了传统的分段测试多次校准带来的误差,且测试数据的连续性较好.在国内完成了器件的1~110 GHz全频段在片测试,基于1~110 GHz在片测试的S参数外推获得的截止频率ft和最大振荡频率f_(max)分别为252 GHz和394 GHz.与传统的测试到40 GHz外推相比,本文外推获得的f_(max)更加准确.这些结果的获得是由于栅长的缩短,寄生效应的减小以及1~110 GHz全频段在片测试的实现.器件的欧姆接触电阻率减小为0.035Ω·mm.     

栅长为83-nm的毫米波低噪声InP基PHEMTs的研制

本文设计并实现了一种83-nm T型栅的InP基In0.52Al0.48As/In0.65Ga0.35As赝配高电子迁移率晶体管（PHEMT）。该器件的总栅宽为2×30μm,展现了良好的DC直流、RF射频以及低噪声特性,包括最大饱和电流密度Idss和最大有效跨导gm,max分别为894mA/mm和1640mS/mm。基于1~110 GHz全频段在片测试的S参数外推获得的最大截止频率ft和最大振荡频率fmax分别为247GHz和392GHz。测得的器件拐点（稳定因子k=1）频率为102GHz,因此,基于拐点外推获得的fmax更加准确。采用冷源法完成器件的在片噪声参数的测试,测得的最小噪声系数NFmin在30GHz时为1dB,相关增益Gass为14.5dB。这些良好结果的获得是由于沟道层中InAs摩尔组分的增加,沟道层厚度的减小,栅长的缩短以及寄生效应的减小。这些优良的特性使得该器件非常适合于毫米波频段低噪声单片集成电路的应用。     

0.1 - 110 GHz在片去嵌技术

研究了0.1 - 110 GHz S参数在片去嵌技术,给出了输入、输出端口非对称下的直通-反射-传输线（TRL）和传输线-反射-匹配（LRM）的去嵌算法求解结果。在 InP衬底上设计了TRL和LRM去嵌标准件,采用两种无源元件验证了去嵌结果的正确性,并且对TRL和LRM在0.1-110 GHz范围内的去嵌准确性进行对比。通过在0.1 - 40 GHz运用 LRM方法,和在75 - 110 GHz运用TRL方法,获得了有源器件HBT两频带内的本征S参数,并对去嵌前和去嵌后提取的小信号电流增益及单向功率增益进行对比。通过插值,可得出待测件0.1 - 110 GHz完整的S参数。     

40GHz 陶瓷衬底SOLT 校准片研制与定标技术研究

在片测试系统在微波单片集成电路MMIC 的设计建模及生产检验中有着必不可少的作用。由于测试 参考面从矢网的同轴接口转移到微波探针,因此需要用共面波导校准片校准。设计制作了用于在片测试系统校准 的陶瓷衬底的SOLT 校准片,并对校准片进行了建模,提取出了1 ~40GHz 频段内片上负载及短路件的等效电阻及寄 生电感参量、直通件的延时参量。片上负载的电阻分量约为45赘,回波损耗在1 ~ 30GHz 小于-20dB;在30 ~ 40GHz 小于-10dB。验证了SOLT 校准片设计、制作及定标的整个工艺过程的有效性。     

3 mm 波段低噪声放大器

基于InP HEMT在3 mm波段的优越的噪声性能,设计制作了一款3 mm波段InP HEMT低噪声放大器。通过合理设计外延材料结构和器件结构,提高器件性能。测试1~40 GHz器件的S参数和噪声参数以及75~110 GHz器件的S参数,并采用外推的方法建立了器件的噪声模型。电路设计采用ADS仿真软件,采用全版图电磁场仿真保证电路设计的准确性,最终实现了一款3 mm波段低噪声放大器。测试结果显示在92~96 GHz时,带内增益大于20 dB,噪声系数小于4.0 dB。芯片面积3.07 mm×1.75 mm,直流功耗60 mW。     

一种用于氮化镓晶体管建模的TRL 校准方法

直通-反射-延迟线(TRL)校准相对于短路-开路-负载-直通(SOLT)校准是一种更加准确且易于实现的 校准方法,尤其适用于二端口及多端口的非同轴测量。文中针对Wolfspeed 公司的氮化镓晶体管CGH40010F 的S 参数 测量问题,分析讨论了TRL 校准在网络分析仪中的误差盒模型,在此基础上设计制作了一套TRL 校准件,其工作频率 范围为1~6 GHz,在此频段内直通和延迟线均达到Sii(i =1,2)幅值小于-15 dB,Sij(i,j =1,2;i≠j)幅值大于-0. 8 dB;将 该校准件特性指标内置到矢量网络分析仪中进行校准测试,实测结果表明,经过TRL 校准后的氮化镓晶体管小信号S 参数与官方数据手册中一致,验证了该校准测量方法及据此设计制作的TRL 校准件是有效的。     

提取共面微波探针S 参数的方法*

共面微波探针是裸芯片测量信号输入/输出的重要媒介,通过与晶圆片物理接触,建立起测量系统与芯片之间 的信号连接通道。为了获得共面微波探针完整准确的S 参数,设计并实现了“两步法”测量方案,首先在同轴端口进行校准,然 后在探针尖端口进行第二步校准。通过与出厂数据进行对比分析,证明了方案的可行性,同时指出在片校准件预校准的重要 性。另外,讨论了氧化铝和砷化镓两种材料在片SOLT 校准件对于探针S 参数提取中的影响,实验显示二者相角偏差达到 39.8°,回波损耗呈现规则性的变化,全部测量数据的频段覆盖1~40 GHz,最终给出了优化的测量方案。     

一种基于RF MEMS开关的四端口电子校准件设计

针对射频多端口器件微波测试需求,基于SOLT校准原理设计了一种工作频率在DC~12 GHz范围内、基于RF MEMS开关的四端口电子校准件。数值仿真结果表明,在短路状态下,器件的回波损耗小于0.15 dB;在直通状态下,器件的插入损耗小于0.5 dB,端口之间的隔离度大于20 dB;在开路状态下,器件的回波损耗小于0.3 dB,端口之间的隔离度大于25 dB;同时采用微表面加工工艺,利用磁控溅射工艺对负载电阻进行了制备,其测试结果约为50 Ω,符合设计要求。设计的基于RF MEMS开关的四端口校准件,具有射频性能好、体积小、易于集成等优点,能够满足X波段微波多端口器件在片测试的应用需求。     

在片LRRM校准件研制及标定

研制了75~110 GHz氧化铝陶瓷衬底在片LRRM校准件,建立了校准件的电路模型。为了实现LRRM校准件高准确度的标定,还研制了多线TRL校准件。通过测量和计算相结合的方式对LRRM校准件中传输线标准的特征阻抗、延时、损耗,反射标准的延时和匹配负载的电阻、电感进行标定。分别采用标定的校准件、研制的多线TRL校准件和商用校准件104-783A对在片S参数测量系统进行校准,测量相同的衰减器和短路标准,结果显示,在75~110 GHz频段传输幅度最大偏差0.07 dB,传输相位最大偏差1.5°,反射幅度最大偏差0.02(线性值),反射相位最大偏差2.9°。     

SiC衬底上栅长70 nm fT / fmax >160 GHz的InAlN/GaN HEMTs器件

在SiC衬底上制备了InAlN/GaN 高电子迁移率晶体管（HEMTs）,并进行了表征。为提高器件性能,综合采用了多种技术,包括高电子浓度,70 nm T型栅,小的欧姆接触电阻和小源漏间距。制备的InAlN/GaN器件在栅偏压为1 V时得到的最大饱和漏电流密度为1.65 A/mm,最大峰值跨导为382 mS/mm。70 nm栅长器件的电流增益截止频率fT和最大振荡频率fmax分别为162 GHz和176 GHz。     

Design of a Compact Ka-band Balanced Mixer Based on a Novel Wide-band Equivalent Circuit of the Schottky Diode

A compact Ka-band balanced mixer based on a novel Schottky diode model is presented in this paper. According to its physical structure, a novel 3D electromagnetic model of the Schottky diode is proposed. Meanwhile, a wide-band equivalent circuit is built, which takes all high frequency effects existing in the diode into account. All the parasitic reactances are extracted from the electromagnetic model-based S-parameters up to 110 GHz. Based on the proposed equivalent circuit, a Ka-band balanced mixer is designed and optimized, where bandpass filters with open stubs and a lowpass filter based on defected ground structure cells are used. The measured results show that the conversion loss is below 9 dB from 30 GHz to 40 GHz with the minimum of 6.7 dB at 35 GHz. The normalized size of the mixer is only 3.3λ _g  × 3.3λ _g , whereλ _g is the wavelength at 35 GHz.     

一种宽带的InGaP/GaAs HBT 再生频率分频器

A dynamic divide-by-two regenerative GaP/GaAs heterojunction bipolar transistors （HBTs） frequency divider （RFD） is presented in a 60-GHz-fT Intechnology. To achieve high operation bandwidth, active loads instead of resistor loads are incorporated into the RFD. On-wafer measurement shows that the divider is operating from 10 GHz up to at least 40 GHz, limited by the available input frequency. The maximum operation frequency of the divider is found to be much higher than fT/2 of the transistor, and also the divider has excellent input sensitivity. The divider consumes 300.85 mW from 5 V supply and occupies an area of 0.47 × 0.22 mm^2.     

Broadband Space Conservative On-Wafer Network Analyzer Calibrations With More Complex Load and Thru Models

An improved vector network analyzer (VNA) calibration approach is demonstrated that utilizes planar lumped short-open-load-thru standards and achieves accuracy comparable to thru-reflect-line (TRL) at high frequency, without the commonly occurring errors in TRL at low frequency. The approach relies on complex load and thru models for coplanar waveguide and microstrip standards that are not currently available in typical VNA firmware. It is shown that the RF performance changes due to variations in fabrication of load can be addressed by “calibrating” or adjusting the load model with the measured dc resistance for a particular load. Good results are shown for a wide range of substrates (GaAs, alumina, and FR-4) and frequencies to 110 GHz.     

A Simplified Calibration Methodology for On-Chip Couplers

In this paper, we propose a simplified calibration methodology for on-chip couplers to de-embed the unwanted but unavoidable parasitics introduced by the probing pads as well as the effects originating from redundant feeding lines. The traditional TRL (Thru, Reflect, Line) calibration technique for single-ended two-port device is extended and applied to symmetrical 4-port devices that can be decomposed as the odd- and even-mode equivalent circuits. Accordingly, the TRL calibration standards in the balanced format are designed as well. As a final step, single-ended 4-port S-parameters of device under test (DUT) are reconstructed through its de-embedded odd- and even-mode 2-port S-parameters. To validate the efficacy of our proposed calibration methodology in extracting S-parameters of DUT, models in HFSS, such as a branch-line coupler and a coupled-line coupler with probing pads, and balanced TRL calibration standards are generated. After performing the de-embedding procedures proposed in this paper, the extracted S-parameters agree well with the simulated S-parameters of DUT without adding any pads and feeding lines for measurement.     

通过TRL校准提取管芯S参数的技术

介绍了一种基于TRL法的提取管芯S参数的方法.该方法从TRL校准出发,实际测量得到封装器件的S参数;管芯以外的参量(管壳及键和线)用等效电路表示,最后用微波仿真软件模拟得到管芯S参数.此方法在没有精确的测试夹具条件下,仍可以得到较理想的器件和管芯S参数.实验证明该方法简便、实用性强,可推广应用于不宜直接测量管芯S参数的器件.     

测量大功率LDMOS晶体管特性的TRL校准方法研究

The impedance and output power measurements of LDMOS transistors are always a problem due to their low impedance and lead widths.An improved thru-reflect-line(TRL) calibration algorithm for measuring the characteristics of L-band high power LDMOS transistors is presented.According to the TRL algorithm,the individual two-port S parameters of each fixture half can be obtained.By de-embedding these S parameters of the test fixture,an accurate calibration can be made.The improved TRL calibration algorithm is successfully utilized to measure the characteristics of an L-band LDMOS transistor with a 90 mm gate width.The impedance of the transistor is obtained,and output power at 1 dB compression point can reach as much as 109.4 W at 1.2 GHz, achieving 1.2 W/mm power density.From the results,it is seen that the presented TRL calibration algorithm works well.