2位GaAs超高速模-数转换电路的设计与制作

模数(A-D)转换电路是信号处理系统中的一种关键性元件。本文结合现有GaAs起高速集成电路工艺,提出了一种2位GaAs A-D转换电路的设计方法,并制作出了单片形式的2位GaAs A/D转换电路。实验结果表明,该电路能正常工作在1Gs/s的转换速率下。它的转换时间小于1.0ns,电路功耗不高于340mW。这说明它在速度和功耗方面已展现出比Si双极电路更为广阔的发展前景。     

Design, fabrication, and evaluation of 2- and 3-bit GaAs MESFET analog-to-digital converter IC's

the analog-to-digital converter (A/D) is a critical component of a signal processing system. GHz-rate A/D's will be required in many future systems. While Si bipolar based A/D's can easily meet 4-6-bit resolution requirements, excessive power dissipation (1 W per bit) limits their operation to 100-400-MHz sampling rates. Recently, GaAs MESFET's have demonstrated high frequency operation with relatively low power dissipation. This paper describes the design of 2- and 3-bit A/D's using GaAs MESFET's. Monolithic integrated A/D circuits were fabricated and successfully operated at gigahertz sampling rates. This sampling rate is the highest reported for any A/D technology at room temperature. The power dissipation is 150-200 mW per bit. With further improvements in comparator sensitivity, the design can be extended to 4-bit A/D for GHz rate operation.     

新型8通道24位模数转换器ADS1216及其应用

介绍了8通道24位△-∑型模拟／数字转换器ADS1216的特点、结构及原理，并以ADS1216用于海洋光学浮标光学幅照度仪为例，给出了它和C8051F020之间的接口电路和程序流程图，最后给出了ADS1216的一些使用要点及设计经验。     

8通道12位串行A/D转换器MAX1202及其应用

介绍了８通道１２位串行Ａ／Ｄ转换器ＭＡＸ１２０２的功能特点和工作过程,并以材料表面喷涂金属薄膜自动控制系统为例,给出了ＭＡＸ１２０２与ＡＴ８９Ｃ２０５１的接口电路及软件设计。     

改善GaAs MESFET输出功率线性的载流子浓度分布设计与制备

经过对GaAs MESFET输出功率及其线性失真的综合分析,提出了无拖尾双峰n~+n载流子浓度分布的最佳设计。用Si离子注入和Be注入埋层方法,以及优化的快速退火技术,满意地制备出所希望的无拖尾双峰n~+n浓度分布。用于DX571功率GaAs MESFET器件时的研究表明,与常规注入分布的器件相比,无拖尾n浓度分布器件在4GHz下测得的1dB增益压缩功率输出增加了0.4W;在输入信号提高50mW情况下增益仍为9dB,漏极效率提高3％,加上n~+注入后饱和压降又下降0.3V,预计其线性输出功率能力将会有进一步改善。     

Si衬底上MBE GaAs MESFET与IC制备

叙述在MBE(分子束外延)GaAs/Si材料上制作GaAs MESFET与Ic的研究。考虑到GaAsIC与Si IC单片集成的需要,采用了Ti/TiW/Au肖特基金属化和Ni/AuGe/Ni/Au欧姆接触金属化,层间介质采用等离子增强淀积氮化硅和聚酰亚胺复合材料。在该工艺基础上,制备了性能良好的GaAs/Si MESFET与IC。     

Design and fabrication of a GaAs vertical MESFET

Vertically oriented GaAs MESFET's were fabricated on thick epitaxial conductive layers grown by molecular-beam epitaxy on a semi-insulating substrate. The vertical channel pattern was defined by electron-beam lithography and included structures as small as 0.3- 0.4 µm on a total period of 1.0 µm. The vertical channels were formed by reactive ion etching, and the gate contact was formed by dual-angle evaporation. The top ohmic contacts were interconnected by a metal bridge supported by a dielectric layer. The drain characteristics displayed a drain punchthrough effect, indicating that a very short gate length was achieved. Microwave measurements indicated a maximum oscillation frequency of 12 GHz.     

10-Gb/s strained MQW DFB-LD transmitter module and superlattice APDreceiver module using GaAs MESFET IC's

This paper describes the design and performance of a 10-Gb/s laser diode (LD) transmitter and avalanche photodiode (APD) receiver, both of which are based on GaAs MESFET IC's. The LD transmitter consists of a strained MQW distributed-feedback LD and one chip LD driver IC. The module output power is +4.6 dBm at 10 Gb/s. The APD receiver consists of an InGaAsP/InAl/As superlattice-APD and an IC-preamplifier with the 10-Gb/s receiver sensitivity of -27.4 dBm. As for the LD transmitter, we discuss the optimum impedance-matching design from the viewpoint of high-speed interconnection between LD and driver IC's. As for the APD receiver, the key issue is input impedance design of preamplifier IC, considering noise and bandwidth characteristics. Total performance of the transmitter and receiver is verified by a 10-Gb/s transmission experiment and a penalty-free 10-Gb/s fiber-optic link over 80 km of conventional single-mode fiber is successfully achieved     

Design and performance of GaAs normally-off MESFET integrated circuits

DC and transient analyses of GaAs normally-off MESFET integrated circuits are described. The design tradeoffs between device parameters and logic characteristics are discussed for an inverter with a resistive load. By increasing the supply voltage to several times that of the built-in voltage, the propagation delay time can be lowered similar to that when using an active load (current source). To investigate the speed-power performance of the IC's, ring oscillators with different fan-in and fan-out configurations were fabricated. A binary frequency divider which uses a master-slave flip-flop was tested. The maximum counting frequency of the divider was 610 MHz at a supply voltage of 1.5 V. This coincides with the results obtained from the ring oscillators with fan-in/fan-out = 2/2. Comparing the experimental results with the theory, the effective electron mobility in the thin channel layer is expected to be very low. By improving the mobility and shortening the gate length to half a micrometer, practical functioning circuits should operate with an average propagation delay time of less than 100 ps.     

GaAs MESFET微波固态振荡器的设计与实现

通过理论计算与CAD的优化仿真实现了一种基于GaAs MESFET微波固态振荡器.电路结构简单、工程实用性强,且易于集成化.由实际测试表明,振荡器的中心频率为4.54 GHz,输出功率为14.95dBm,在200kHz下的相位噪声为-124.26 dBc/Hz.     

GaAs双栅MESFET的设计与性能分析

本文将双栅MESFET模拟成两个级联的单栅MESFET,用三端信号流通图来分析它的性能特征.并将双栅MESFET当作一个短的行波管来说明其工作原理的物理本质.可以看出,它是一种在微波领域中有着广泛用途的多功能器件.本文还讨论了GaAs双栅MESFET的设计.采用金属剥离工艺制作的双指状、深凹糟1微米栅的双栅MESFET,在4千兆赫下相关增益为20分贝,噪声系数为1.9分贝,在8千兆赫下相关增益为18分贝,噪声系数为2.8分贝.     

Design of GaAs MESFET Oscillator Using Large-Signal S-Parameters

A design method of GaAs MESFET oscillator using large-signal S-parameters has been discussed. Together with the measurement results of the dependence of Iarge-signall S-parameters on power levels and bias conditions, computer analysis of the equivalent circuit for MESFET'S has qualitatively clarified the large signal properties of MESFET'S. On the basis of these findings, S-parameters have been designed for the MESFET oscillator over the frequency range of 6-10 GHz, which has resulted in power output of 45 mW at 10 GHz with 19-percent efficiency, and 350 mW at 6.5 GHz with 26-percent efficiency, respectively. Good agreements between predicted and obtained performances of MIC positive feedback oscillator have been ascertained, verifying the validity of the design method using large-signal S-parameters.     

一种用于14 bit SAR ADC的DAC设计

本文设计了用于14bit逐次逼近型模数转换器（SAR ADC）的DAC电路。针对该DAC,介绍一种全差分分段电容阵列结构以缩小DAC的版图面积;高二位权电容采用热码控制,用以改善高位电容在转换时跳变的尖峰以及DAC的单调性;对电容阵列采用数字校准技术,减小电容阵列存在的失配,以提高SAR ADC精度。校准前,SAR ADC的INL达到10LSB,DNL达到4LSB;与校准前相比,校准后,INL〈0.5LSB,DNL〈0.6LSB。仿真结果表明,本DAC设计极大改善SAR ADC的性能,已达到设计要求。     

一种K波段GaAs MESFET压控振荡器的设计

利用微波晶体管的负阻特性,基于Agilent ADS软件,设计出一种K波段微带结构、变容管调谐的MESFET压控振荡器(VCO)。对VCO进行实测．结果表明,VCO的中心频率为20.56GHz,调频带宽大于100MHz,带内输出功率大于2mW,相位噪声大于-90dBc／Hz@100kHz,满足实际应用。     

On Design and Performance of Lossy Match GaAs MESFET Amplifiers

The noise figure, the gain, and the reflection coefficients of lossy match amplifiers and their dependence on circuit elements are studied. Theoretical results are supported by measured data taken on a two-stage unit. In addition, the performance characteristics of a 100-8800 MHz four-stage lossy match amplifier are discussed. The unit exhibits 23.3 +- 1.1 dB of gain over the nearly 6-1/2 octaves. Its maximum noise figure is 10.9 dB from 100-8800 MHz and 6.6 dB from 2000-8000 MHz. The amplifier's overall circuit dimensions are 10 X 5.7 mm..     

GaAsMMIC双栅MESFET混频器设计与实验研究

对微波单片集成 (简称 MMIC)双栅 MESFET混频器的设计理论和工艺技术进行较为细致的研究。根据双栅 MESFET的理论分析与实验结果 ,建立了一种栅压调制 I- V特性的经验模型 ,推导了双栅 FET混频器变频增益公式。分析了栅压对改变非线性跨导在混频器中的作用。最后设计并加工出了芯片面积为 0 .75 mm× 1 .5 mm Ga As MMIC双栅 FET混频器。     

SAD0820高速8位A／D转换器的设计与分析

ＳＡＤ０８２０高速８位Ａ／Ｄ转换器是一种具有跟踪／保持功能的８位高速微机兼容Ａ／Ｄ转换器，其转换时间为１．５ｕｓ，功耗为７５ｍＷ，用串并结构来实现Ａ／Ｄ转换器的高速。每４位ＡＤＣ分别由１５个比较器构成；单一电源工作，采用双层多晶硅ｐ阱ＣＭＯＳ工艺制作。     

一种12位高速低失真数字/模拟转换器的设计

介绍了一种12位高速、低失真数字/模拟转换器(DAC)的设计原理及其电路结构;着重阐述了去毛刺技术及其应用。采用2μm等平面隔离互补双极工艺模型参数进行了Cadence仿真。结果表明,该12位DAC在高达60MHz数据更新率下具有低于100pV·s的毛刺脉冲面积。     

GaAs Power MESFET's: Design, Fabrication, and Performance

This paper reviews the state of the art of power GaAs MESFET's. Items that will be covered are the operating principles of the device from a material and geometric point of view, the design, fabrication sequences, and material structures used by various laboratories, the factors identified as important to power by workers in the field the performance of the device in terms of frequency effects, power per unit gate-width effects, scaling from small to large gate-width devices, and voltage effects. In addition, the circuit applications of GaAs FET's will be briefly discussed.     

一种超高速10位D/A转换器的设计

设计了一种超高速差分电流舵10位D/A转换器.该D/A转换器电路由8路分时复用器、5-31"温度计"译码器、快速转换电流开关和恒流源阵列等单元组成,采用0.35 μm SiGe BiCMOS标准工艺制造.该10位D/A转换器的数据更新率达到1 GSPS.介绍了电路实现原理和各单元的结构及设计思想,给出了电路仿真结果,并对实际电路进行了测试和分析.结果表明,该10位D/A转换器具有精度高、速度快、通用性强等优点.