宽频率范围的单子带压控振荡器设计

基于TSMC 180 nm CMOS工艺,提出了一种振荡频率为2~3 GHz的宽频率范围、低相位噪声的单子带压控振荡器(VCO)。采用双平衡吉尔伯特混频结构,将单子带5~6 GHz压控振荡器与固定频率3 GHz压控振荡器进行下混频,可得到振荡频率为2~3 GHz的单子带压控振荡器,实现相对带宽从18.18%到40%的展宽。其中5~6 GHz单子带压控振荡器采用互补交叉耦合结构,更易达到起振条件,采用两组可变电容的并联形式以提高调谐曲线的线性度,拓宽压控振荡器的输出频率调谐范围。通过芯片测试验证,在1.8 V电源电压下,调谐电压变化范围为0.6~2.8 V时,实际输出频率范围为1.85~3 GHz,最大调谐灵敏度为1000 MHz/V,2 GHz频点处相位噪声为-123.2 dBc/Hz@1 MHz,芯片尺寸为1.2 mm×0.7 mm。     

一种适用于2 4GHz ISM射频波段的全集成CMOS压控振荡器

提出了一种频率可调范围约 2 30MHz的全集成LC压控振荡器 (VCO) .该压控振荡器是用 6层金属、0 18μm的标准CMOS工艺制造完成 .采用MOS晶体管和电容组合来实现等效变容管 ,为降低芯片面积仅使用一个片上螺旋电感 ,并实施了低电压、低功耗的措施 .测试结果表明 ,该压控振荡器在电源电压为 1 8V的情况下功耗约为10mW ,在振荡器中心频率为 2 46GHz时的单边带相位噪声为 - 10 5 89dBc/Hz @6 0 0kHz .该压控振荡器可以应用于锁相环电路或频率综合器中.     

基于0.2μm GaAs PHEMT工艺的压控振荡器IC设计

给出了一个采用0 2μmGaAsPHEMT工艺设计的全集成差分负阻式LC压控振荡器电路,芯片面积为0 52×0 7mm2。采用3 3V正电源供电,测得输出功率约-11 22dBm,频率调节范围6 058GHz～9 347GHz;在自由振荡频率7 2GHz处,测得的单边带相位噪声约为-82dBc/Hz@100kHz.     

基于GaAs工艺的36GHz压控振荡器

利用法国OMMIC公司的0.2μm GaAs PHEMT工艺,设计实现了一个36GHz压控振荡器电路.该电路采用完全差分的调谐振荡器结构,通过引进容性源极耦合差动电流放大器和调谐负载电路,提高了电路的性能.测试表明:该压控振荡器中心频率为36GHz,调谐范围约为800MHz,在偏离中心频率10MHz处的单边带相位噪声为-98.83dBc/Hz.芯片面积为0.5mm×1mm,采用-5V单电源供电,核心单元功耗约为200mW.     

基于GaAs工艺的36GHz压控振荡器

利用法国OMMIC公司的0.2μm GaAs PHEMT工艺,设计实现了一个36GHz压控振荡器电路.该电路采用完全差分的调谐振荡器结构,通过引进容性源极耦合差动电流放大器和调谐负载电路,提高了电路的性能.测试表明:该压控振荡器中心频率为36GHz,调谐范围约为800MHz,在偏离中心频率10MHz处的单边带相位噪声为-98.83dBc/Hz.芯片面积为0.5mm×1mm,采用-5V单电源供电,核心单元功耗约为200mW.     

基于电容补偿的高线性低噪声2.4GHz CMOS LC 压控振荡器

实现了一个基于标准0.18µm CMOS工艺的2.4GHz高线性低噪声交叉耦合LC压控振荡器。基于三段分布式偏置的开关容抗管电路和差分开关电容电路,提出了一种调谐灵敏度补偿结构,减小了压控振荡器的增益变化,获得了高线性度和良好的相位噪声性能。与传统结构的压控振荡器相比,本文提出的压控振荡器在整个频率调谐范围内具有更加恒定的增益。当载波频率为2.42GHz 时,在100kHz和1MHz的频偏处相位噪声分别为-100.96dBc/Hz和-122.63dBc/Hz。工作电压为1.8V时,电路功耗为2.5mW。该压控振荡器面积为500×810 µm2。     

W波段InP DHBT宽带高功率压控振荡器（英文）

成功实现了一款具有高输出功率和宽频率调谐范围的基波压控振荡器.其制作工艺为0. 8μm InP DH-BT工艺,晶体管的最大fT和fmax分别为170和250 GHz.电路核心部分采用了为高频应用改进的平衡式考毕兹拓扑,在后面添加一级缓冲放大器来抑制负载牵引效应,并提升了输出功率. DHBT的反偏CB结作为变容二极管来实现频率调谐.芯片测试结果表明,压控振荡器的频率调谐范围为81～97. 3 GHz,相对带宽为18. 3%.在调谐频率范围内最大输出功率为10. 2 dBm,输出功率起伏在3. 5 dB以内.在该压控振荡器的最大调谐频率97. 3 GHz处相位噪声为-88 dBc/Hz@1MHz.     

低功耗CMOS差分环形压控振荡器设计

提出了一个基于0.18μm标准CMOS工艺实现的四级差分环形压控振荡器.全差分环形压控振荡器采用带对称负载的差分延时单元.仿真结果表明,压控振荡器的频率范围在最坏情况为0.21～1.18GHz;偏离中心频率10MHz情况下,压控振荡器的相位噪声为-118.13dBc/Hz; 1.8V电源电压下,中心频率为600MHz时,压控振荡器的功耗仅有4.16mW;版图面积约为0.006mm2.可应用于锁相环和频率综合器设计中.     

万兆以太网物理层全集成单片锁相环电路

给出了一个采用 0 .2μm Ga As PHEMT工艺实现的单片集成高速锁相环电路。芯片采用差分电感电容谐振式负跨导压控振荡器 ,总面积为 0 .9mm× 0 .7mm。采用 3.3V单电源供电 ,测得芯片总功耗为 2 83m W,输出功率约 - 1 1 d Bm,中心频率 7.2 GHz,锁定范围为± 30 0MHz。环路锁定在 7.2 GHz时 ,输出信号的峰 -峰抖动约 5 .6ps,在 5 0 k Hz频偏处的单边带相位噪声为 - 94d Bc/Hz。本锁相环电路经适当修改可应用于万兆以太网物理层 IEEE80 2 .3ae1 0 GBASE- R或 1 0 GBASE- W时钟恢复电路。     

多相位低相位噪声5GHz压控振荡器的设计

采用TSMC 0.18μmCMOS工艺实现了全差分相位差为 450 的 LC低相位噪声环形压控振荡器电路。芯片面积 1.05 mm×1.00 mm。当仅对差分输出振荡信号的一端进行测试时, 自由振荡频率为5.81 GHz, 在5 MHz频偏处的相位噪声为-101.62 dBc/Hz。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

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