利用Cadence设计COMS低噪声放大器

结合一个2.4 GHz CMOS低噪声放大器(LNA)电路,介绍如何利用Cadence软件系列中的IC 5.1.41完成CMOS低噪声放大器设计.首先给出CMOS低噪声放大器设计的电路参数计算方法,然后结合计算结果,利用Cadence软件进行电路的原理图仿真,并完成了电路版图设计以及后仿真.仿真结果表明,电路的输入/输出均得到较好的匹配.由于寄生参数,使得电路的噪声性能有约3 dB的降低.对利用Cadence软件完成CMOS射频集成电路设计,特别是低噪声放大器设计有较好的参考价值.     

433MHz ASK接收机射频前端电路设计

设计了一款应用在433MHz ASK接收机中的射频前端电路。在考虑了封装以及ESD保护电路的寄生效应的同时,从噪声、匹配、增益和线性度等方面详细讨论了低噪声放大器和下混频器的电路设计。采用0.18μm CMOS工艺,在1.8V的电源电压下射频前端电路消耗电流10.09 mA。主要的测试结果如下:低噪声放大器的噪声系数、增益、输入P1dB压缩点分别为1.35 dB、17.43 dB、-8.90dBm;下混频器的噪声系数、电压增益、输入P1dB压缩点分别为7.57dB、10.35dB、-4.83dBm。     

一种改进的高线性CMOS混频器的分析与设计

在多标准系统应用中,由于线性度和噪声的要求,使得混频器的设计难度很大。采用2次谐波注入结构的3阶失真抵消技术,设计了一种改善跨导级线性度的高线性CMOS混频器。在混频器开关级处引入LC滤波电路,抵消了开关级晶体管的2阶和3阶互调失真,进而优化了开关级的线性度。采用TSMC 0.13 μm CMOS工艺进行设计与仿真,并完成了版图设计与流片。较之传统的吉尔伯特混频器,该电路的输入3阶交调点IIP3增加了11.2 dBm,达到9.2 dBm的高线性度,对噪声系数、增益以及功耗造成的影响较小。     

应用于GSM/EDGE零中频接收机的CMOS射频前端

介绍了一个零中频接收机CMOS射频前端,适用于双带(900MHz/1800 MHz)GSM/EDGE;E系统.射频前端由两个独立的低噪声放大器和正交混频器组成,并且为了降低闪烁噪声采用了电流模式无源混频器.该电路采用0.13 μm CMOS工艺流片,芯片面积为0.9 mm×1.0 mm.芯片测试结果表明:射频前端在90...     

一种宽带低噪声放大器的设计

随着无线通信的迅猛发展,提高了对射频技术的要求。本文就射频前端的低噪声放大器设计进行研究和分析,并且进行了流片生产和测试。首先进行了基础理路的研究分析,通过仿真电路满足性能,最后再通过流片测试得到结论。本文中对其带宽以及噪声系数进行了测试并且与预期效果很接近。通过本文设计得到了带宽为近1.5GHz,其增益的大小为23.2dB。     

一种应用于GPS射频前端的低噪声混频器

为了克服混频器噪声对GPS接收机灵敏度造成的影响,设计了一种应用于GPS射频前端的低噪声混频器电路.采用自偏置缓冲级放大本振信号,有效地提高了电路性能.该混频器的转换增益为23 dB,噪声系数为4.55 dB,3阶交调点为-9.36 dBm,在1.57 GHz到1.6 GHz频段上,反射系数S11小于-15 dB,电路采用1.8 V电压供电;混频器核心电路静态工作电流1.2 mA,采用CMOS 0.18 μm工艺实现,芯片版图面积为160μm×360μm.     

一种0.18μm CMOS工艺单电感单模块正交卫星导航接收机射频前端设计

本文介绍了一种改进的单模块化卫星导航射频前端模块的设计.该结构将低噪声放大器,混频器以及压控振荡器层叠级联,并实现电流和功能的复用.仅采用了单个片上螺旋电感作为LC振荡回路,另外增加一个二分电路作为正交本振信号的产生源.文章讨论了该模块的增益规划,噪声系数,以及设计的细节.对相位噪声以及功耗进行了改进.通过0.18μm CMOS射频工艺进行流片验证,获得带内平均噪声系数为5.4dB,增益43dB,三阶交调点-39dBm.测得相位噪声在本振1MHz偏移处小于-105dBc/Hz.整体功耗小于19.8mW,工作电压为1.8V.实验结果证明满足卫星导航射频前端应用的需要.     

一种新型900 MHz下混频器的设计

设计了一种用于超高频射频识别(UHF RFID)读写器的新型低功耗、低噪声、高线性度900 MHz下混频器.在输入端采用2阶交调注入结构,以提高线性度;在输出端采用动态电流注入结构,获得了很好的噪声特性,且具有很高的增益.采用Chartered 0.18 μm标准CMOS模型对电路进行仿真,电路的供电电压为1.2 V.仿真结果表明,设计的900 MHz下混频器增益为11 dB,IIP3为-3.5 dBm,噪声为11 dB.     

一种基于0.18μm CMOS工艺用于卫星导航系统射频前端双模低噪声放大器设计

本文介绍了一种用于全球卫星导航系统射频前端的双频点低噪声放大器的设计,讨论了针对双频点或多频点的低噪声放大器的设计方法,分析了具体的电路设计和相关参数的确定并进行仿真.采用台积电0.18um 1P4M射频CMOS工艺进行流片验证,低噪声放大器噪声特性可分别在两个频点1.27GHz和1.575GHz处达到16.8dB和18.9dB,实测噪声系数可达1.5dB~1.7dB之间.此结构在1.8V工作电压下,电流小于4.3mA.流片结果与原设计情况相符,完全满足射频前端接收机的需求.     

低频低噪声集成运放XD1531的设计和分析

本文阐明了低频低噪声运放XD1531的设计原理。从电路和版图设计两方面论述了该电路整个设计过程。针对电路第一级的结构,采用低频低噪声方法进行设计。在版图方面主要考虑了降低低频噪声,尤其是降低表面1/f噪声的措施。通过对XD1531噪声性能的分析以及与国内外同类产品的比较,说明了该集成电路具有低噪声特性。同时,说明本文提出的设计方法对于降低集成电路的低频噪声是有效的。     

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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正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its