用于便携式GPS接收机中的5.4mW低噪声高增益CMOS射频前端电路设计

设计了应用于便携式GPS接收机射频前端中的CMOS低噪声放大器和正交混频器. 该电路中的低噪声放大器采用带源端电感负反馈的输入级,并引入功耗约束下的噪声和输入同时匹配技术. 正交混频器基于吉尔伯特单元. 电路采用TSMC 0.18μm RF CMOS工艺实现,总的电压转换增益为35dB,级联噪声系数为2.4dB,输入1dB压缩点为-22dBm,输入匹配良好,输入回损为-22.3dB, 在1.8V电压供电下,整个全差分电路功耗为5.4mW.     

用于便携式GPS接收机中的5.4mW低噪声高增益CMOS射频前端电路设计

设计了应用于便携式GPS接收机射频前端中的CMOS低噪声放大器和正交混频器.该电路中的低噪声放大器采用带源端电感负反馈的输入级,并引入功耗约束下的噪声和输入同时匹配技术.正交混频器基于吉尔伯特单元.电路采用TSMC 0.18μm RFCMOS工艺实现,总的电压转换增益为35dB,级联噪声系数为2.4dB,输入ldB压缩点为-22dBm,输入匹配良好,输入回损为-22.3dB,在1.8V电压供电下,整个全差分电路功耗为5.4mW.     

一种ISM 2.4GHz的低功耗低中频射频接收机前端

本文描述了一种工作在2.4GHz ISM频段的低功耗、低中频射频接收机前端电路,使用TSMC 0.13um CMOS工艺。整个前端包括一个低噪声放大器以及两次变频下变换混频器。低噪声放大器通过在输入级引入额外的栅-源电容实现了低功耗与低噪声的设计;在下变换混频器设计中,分别使用一个单平衡射频混频器以及两个双平衡低中频混频器实现两次变频下变换技术;射频混频器输入晶体管源极串联电感-电容谐振网络以及低噪声放大器输出级的电感-电容谐振网络总共实现了30dB的镜像抑制率。整个前端占用芯片面积约0.42mm2,在1.2V的供电电压下,仅耗功率4.5mW,实现了4dB的噪声系数,在高增益模式下,获得-22dBm的三阶交调线性度,整个链路电压增益为37dB。     

差分式低电压高增益电流模式集成射频接收机前端

本文提出了一种用于802.11 b 无线局域网的差分式低电压该增益电流模式射频前端集成电路。该电路包含一个差分式跨导低噪声放大器和一个差分式电流模式下混频器。单边跨导低噪声放大器仅含一个MOS晶体管和2个电感、2个电容构成。放大器中的栅-源并联电容Cx1 和 Cx2 不仅能减小栅-源寄生电容对谐振频率和输入匹配阻抗的的影响,而且能使得栅电感的取值变小。电流模式混频器由开关电流镜构成。调节开关电流镜晶体管之间沟道尺寸比值可以增加混频器的增益,从而增大射频接收机前端的功率增益。该射频前端电路工作在1V的电源电压下。使用chartered 0.18μm CMOS工艺进行了流片。 对芯片进行测试得到该射频前端的功率增益为17.48 dB, 输入三阶交调截点 (IIP3) 为 -7.02 dBm. 后仿真表示该芯片的噪声系数为4.5 dB,功耗仅为 14mW。     

0.18μm CMOS X波段接收机射频前端设计

本文给出了一个采用TSMC 0.18 m CMOS工艺应用于X波段SAR(合成孔径雷达)的单片接收机射频前端的设计。接收机前端由低噪声放大器和混频器组成,低噪声放大器工作在9 GHz~11GHz,混频器将10GHz的射频信号转换到2GHz中频,本振信号由片外提供。在X波段频率下,尽管CMOS 0.18μm工艺特征频率比较低,工作仍然实现了低噪声系数,提高了集成度。测试结果表明,本设计在300MHz的带宽上实现了20dB的转换增益,噪声系数达到2.7Db,输入1dB压缩点达到-19.2dBm,在1.8V的电源电压下前端消耗26.6mA电流,芯片面积为1.3×0.97mm2。     

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.     

应用于TD-SCDMA/LTE/LTE-Advanced收发机的多频多模CMOS射频接收前端电路设计

设计了应用于TD-SCDMA/LTE/LTE-Advanced收发机中的多频段、多模式射频接收前端电路. 该前端电路采用直接变频结构,包含两个可调谐差分低噪声放大器、一个正交混频器和两个中频放大器。其中,两个独立的可调谐低噪声放大器覆盖了4个射频频段,在较低的功耗下实现足够的增益和噪声性能. 并且利用开关电容阵列来调节低噪声放大器的谐振频率点. 低噪声放大器通过混频器的驱动级跨导晶体管实现结合。正交混频器采用折叠式双平衡吉尔伯特结构,利用PMOS晶体管作为本振信号的开关对,从而降低1/f噪声. 前端电路具有3种增益模式以获得更大的动态范围. 模式配置和频段选择功能都由片上的SPI模块控制. 该射频前端电路采用TSMC0.18um RF CMOS工艺实现,芯片面积为1.3 mm2. 全部频段上测量的转换增益高于43dB,双边带噪声系数低于3.5dB. 整个电路在1.8V供电电压下,消耗电流约31mA。     

一种高性能宽带直接变频射频前端设计

提出一种宽带(250 MHz~4.7 GHz)无电感BiCMOS射频前端结构,包含低噪声跨导放大器(LNTA)、带电阻无源混频器和跨阻级。低噪声跨导放大器使用了噪声和线性度消除技术,例如输入交叉耦合结构、互补输入和电流复用技术。带电阻无源混频器采用退化电阻来提高线性度。仿真结果表明, 当电源电压为3.3 V时,总电流为9.38 mA, 噪声系数为9.8 dB(SSB),电压转换增益为20 dB,输入3阶交调为+11.8 dBm。     

4·2GHz CMOS射频前端电路设计

设计并实现了一个工作在4.2 GHz的全集成CMOS射频前端电路,包括可实现单端输入到差分输出变换的低噪声放大器和电流注入型Gilbert有源双平衡混频器.电路采用SMIC 0.18 μm RF工艺.测试结果表明,在1.8 V电源电压下,电路的功率增益可达到26 dB,1 dB压缩点为-27 dBm,电路总功耗 (含Buffer) 为21 mA.     

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。     

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.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.