A fully integrated multi-band ED-mode pHEMT VCO using variable transformer and switched resonator

A systematic approach to the design of a reconfigurable LC-coupled voltage-controlled oscillator (VCO) is proposed in this article. The focus is on the choice of the reactive elements of the resonance tank which are most suitable to switch to the desired oscillation frequencies. The optimum Q of the tank will be determined by the selected component. We report a 0.5-µm enhancement–depletion (ED) mode pHEMT (HEMT, high-electron mobility transistor) multiple-frequency VCO, and the generation of multiple frequencies are achieved using switched resonator topology. LC-tank circuit is built by square transformers. By careful selection of the reactive elements, evenly distributed results showed at each designed band. The multi-band ED-mode pHEMT VCO showed the output power of ?4.7?dBm for 2?GHz band, ?6.67?dBm for 3.86?GHz band and ?5.9?dBm for 4.5?GHz band, respectively. The phase noises at 1?MHz offset frequency from carrier were ?112.8?dBc/Hz for 2?GHz, ?105?dBc/Hz for 3.86?GHz and ?103.3?dBc/Hz for 4.5?GHz, respectively. The total chip size is only 1.17?×?0.83?mm².     

单片集成的增强型和耗尽型pHEMT技术

随着射频/微波器件的快速发展及其应用领域的日益扩大,基于半导体单片集成技术的多种器件集成工艺不断发展。研究了一种采用AlGaAs-InGaAs的砷化镓化合物衬底。琥珀酸湿法蚀刻工艺对器件电性能影响较小。将耗尽型和增强型赝配高电子迁移率晶体管(pseudomorphic High-Electron-Mobility Transistor, pHEMT)器件集成于同一芯片半导体工艺技术。结果表明,增强型晶体管Y型栅极的线宽为0.25 m,开启电压为0.3 V;耗尽型晶体管栅极的线宽为0.5 m,开启电压为-0.8 V,实现了在同一芯片上集成从负到正的栅极电压分布,为设计者提供了更为宽广的设计平台。这种集成技术可以应用于低噪声放大器、线性天线开关、滤波器以及功率控制装置等领域。     

60GHz高增益宽带单片集成低噪声放大器

基于0.15μm GaAs pHEMT工艺,设计和制作了一款宽带单片集成低噪声放大器.放大器设计采用四级级联的拓扑结构以获得高增益.芯片尺寸2mm×lmm.实测性能指标为:工作频段45～65GHz,增益18±1.5dB,输入驻波比小于3,输出驻波比小于2.3,直流功耗96mW.在增益、带宽和功耗上达到国际现有产品指标.该芯片可被应用于60GHz宽带无线通信系统.     

高温及关态应力条件下GaAs pHEMT器件的性能退化研究

研究了高温和电学应力下砷化镓赝晶高电子迁移率晶体管的直流特性退化机理。高温下陷阱辅助发射电流引起器件关态漏电上升,而载流子迁移率的退化引起跨导降低;当温度达到450 K时,栅金属的沉降效应会导致跨导异常升高。进一步研究了不同温度下关态电学应力对器件性能退化的影响,结果与高温下栅沉降效应相吻合。     

基于改进的垂直型同轴微带转换的Ku频段平衡低噪声放大器

提出了一种垂直型同轴微带转换的宽带补偿方法,并应用于一款Ku频段平衡低噪声放大器(LNA)的研制。放大器包含波导同轴转换、同轴微带转换、由2级pHEMT 管芯及分支线耦合桥组成的前级放大器以及由MMIC 放大器实现的后级放大器。在13.5 ~14.5 GHz 频率范围内,2 批次累计55 套低噪声放大器的噪声系数小于1.5 dB、增益分布在44.5 ~46.5 dB之间,增益平坦度小于0.6 dB,批次间性能一致性良好。     

Harmonics suppression investigations of pHEMT single-pole-single-throw switches using multi-gate structures

In this study, multi-gate GaAs pseudomorphic high electron mobility transistor (pHEMT) single-pole-single-throw (SPST) microwave switches were implemented and characterized for high power operation. The switch size is not only minimized by employing the compact zigzag layout structure but also with gate finger parallel bar structure for increasing power handling capability. The measured RF and harmonic powers suppression results was analyzed, the parameters of OFF-state (gate bias = −3 V) small-signal model were extracted for single-, dual-, triple- and quadruple-gate switch devices individually. Under ON-state (gate bias = 0 V) operation, the insertion loss performance is slightly worse due to the increasing of gate number and results in the rising ON-state resistance (R_ON). However, the isolation performance can be enhanced by 4 dB from the single-gate device to the triple-gate one. The quadruple-gate device demonstrates only 0.2 dB improvement in isolation performance than the triple-gate one, but it slows the improvement of harmonic suppression level owing to the increasing of the gate-to-gate coupling capacitance.     

一种采用砷化镓pHEMT工艺的超宽带DC-40GHz 4位单片数字衰减器

介绍了一种超宽带DC-40GHz的4位单片数字衰减器。该衰减器采用0.25μm砷化镓pHEMT工艺制造。据我所知,这种衰减器是至今国内文献报道中带宽最宽的。它通过采用适当的结构来得到超宽的带宽、低插入损耗以及高衰减精度。该衰减器具有1 dB的衰减步进和15 dB的衰减动态范围,插入损耗在40 GHz时小于5 dB,全衰减态及全频带内的输入输出回波损耗大于12 dB。     

A Ka-band low-noise amplifier with a coplanar waveguide(CPW)structure with 0.15-μm GaAs pHEMT technology

This investigation explores a low-noise amplifier(LNA) with a coplanar waveguide(CPW) structure,in which a two-stage amplifier is associated with a cascade schematic circuit,implemented in 0.15-μm GaAs pseudomorphic high electron mobility transistor(pHEMT) technology in a Ka-band(26.5-40.0 GHz) microwave monolithic integrated circuit(MMIC).The experimental results demonstrate that the proposed LNA has a peak gain of 12.53 dB at 30 GHz and a minimum noise figure of 3.3 dB at 29.5 GHz,when biased at a V_(d...     

使用0.15微米砷化鐌高速電子遷移率電晶體技術配合共平面波導結構研製Ka頻帶低雜訊放大器

本篇論文研究使用串接電路與共平面波導結構配合0.15微米砷化鐌高速電子遷移率電晶體技術研製Ka(26.5 - 40.0 GHz)頻帶低雜訊放大器。研究結果顯示電晶體偏壓在Vds=2V、Vgs= -0.6V時,在30GHz得到增益12.53dB和29.5GHz得到雜訊3.3dB,實驗得到此技術具有寬頻、高增益與氐雜訊特性,非常適用於毫米波積體電路應用。