Design and Analysis of a Performance-Optimized CMOS UWB Distributed LNA

In this paper, the systematic design and analysis of a CMOS performance-optimized distributed low-noise amplifier (DLNA) comprising bandwidth-enhanced cascode cells will be presented. Each cascode cell employs an inductor between the common-source and common-gate devices to enhance the bandwidth, while reducing the high-frequency input-referred noise. The noise analysis and optimization of the DLNA accurately accounts for the impact of thermal noise of line terminations and all device noise sources of each CMOS cascode cell including flicker noise, correlated gate-induced noise and channel thermal noise on the overall noise figure. A three-stage performance-optimized wideband DLNA has been designed and fabricated in a 0.18-mum SiGe process, where only MOS transistors were utilized. Measurements of the test chip show a flat noise figure of 2.9 dB, a forward gain of 8 dB, and input and output return losses below -12 dB and -10 dB, respectively, across the 7.5 GHz UWB band. The circuit exhibits an average IIP3 of -3.55 dBm. The 872 mum times 872 mum DLNA chip consumes 12 mA of current from a 1.8-V DC voltage.     

Parametric Programming Applied to Reliability Optimization Problems

In practical reliability optimization models, finding an optimal solution to the model is not the only requirement. One may also be interested in solutions that are close to optimum, or one may want to know what happens if a change is made in the model. This paper presents new reliability optimization models which can be formulated as parametric nonlinear integer programming problems. Solution methods are illustrated with examples and flow charts.     

印制电路板的可靠性设计

分析了高速、高密度的印制电路板(PCB)设计中所涉及的可靠性问题，介绍了如何进行PCB可靠性设计的基本方法。     

Optimization of System Reliability Using a Parametric Approach

This paper presents a new method for the optimization of system reliability with linear constraints, using the parametric approach [1]. The classical nonlinear programming technique is used for the solution. This method, which is analytically complete, sufficiently accurate and computationally simple, gives optimum or near optimum design. The procedure is illustrated with examples, and flow charts for the problems are given.     

IMPATT Diode Circuit Design for Parametric Stability

A new approach to IMPATT diode circuit design to achieve freedom from parametric instabilities is described. Necessary and sufficient conditions are described in the frequency domain for the load impedance presented to the diode terminals. A number of unconditionally stable circuits have been developed for flat-profile GaAs diodes using this approach. Three of these circuits have been built and tested experimentally in 11-GHz IMPATT oscillators and amplifiers. These experimental circuits have been free of parametric instability, even when driven into full RF saturation. In a systems application practical constraints such as cost, RF loss, and tunability will require compromises which will degrade the stability, and it may not always be possible to achieve complete stability for a given diode.     

A Design Theory for Wide-Band Parametric Amplifiers

A new exact design theory for a nondegenerate parametric amplifier with double-tuned signal circuit and single-tuned idler circuit is described. If the resistance of the signal circuit, which is neglected in previous papers, is considered, there exists a frequency band in which the amplifier gain is positive. In this paper the band characteristics of the gain are related to this frequency band. Slope parameters of the idler and signal circuits are normalized by the slope parameters which are associated with the diode itself. These normalized slope parameters are used to relate the actual circuit and gain-bandwidth characteristics. The slope parameter of the external signal resonator is related to the negative slope parameter of the diode, and bounds on this ratio are given over which stable amplification is possible. A design table which gives the coupling ratio and slope parameter of the external signal resonator is derived by computer calculation. Experiments were made at 19 GHz. Positive-gain bandwidth was around 4.0 GHz, and flat bandwidth at 10-dB gain was 2.4 GHz. The ratio of these bandwidths coincided with the theory.     

PCB的热设计

基于关系型数据库（RDBMS）的空间数据的存储管理，已成为构建空间数据库的主流技术，主要介绍了基于Oracle8i来构建空间数据库的一些关键技术。     

印制电路板的热可靠性设计

可靠的热分析、热设计是提高印制电路板热可靠性的重要措施。在分析热设计基本知识的基础上，讨论了散热方式的选择问题和具体的热设计、热分析技术措施。     

现代电子设备的可靠性设计技术

可靠性设计是现代电子设备可靠性保证体系的关键环节。阐述了电子设备可靠性设计的基本原则与实施途径，包括元器件的可靠性选用、电子线路的可靠性设计以及印制电路板的可靠性设计等。     

Electronic System Thermal Design for Reliability

Thermal design and analysis are important in Reliability/Availability/Maintainability R/A/M programs for electronic systems. A thermal design approach emphasizing the coupling of heat transfer theory and experiment to basic reliability considerations is illustrated here by discussing typical thermal problems on several system integration levels for a high reliability, multi-cabinet hybrid computer system. This paper emphasizes a particular attitude toward the thermal aspects of equipment design, one that is flexible in the methods of analysis, comprehensive in its treatment of each integration level in a complementary fashion, and oriented toward the goals of the R/A/M program as a whole. The examples show that conventional analytic solutions, when coupled with reliability theory and a modicum of experimental results, lead to effective thermal design.     

Broad-Band Cavity-Type Parametric Amplifier Design

This paper tells how maximum bandwidth can be obtained from a nondegenerate parametric amplifier which utilizes a circulator. Expressions are derived for the gain bandwidth product and maximum possible gain bandwidth product. It is then shown how the Q of the cavities used for the signal and idler circuits may be kept at a minimum without degrading the noise performance of the amplifier. It is shown that best performance results when the TEM mode is used in coax, or, if waveguide is used, when the operating frequency is far away from the waveguide cutoff frequency. The diode used should have as high a self-resonant frequency as possible and the line admittance should be approximately the diode susceptance. Using a diode with a self-resonant frequency at the idler frequency will be seen to give optimum performance. This paper also discusses double tuning the signal circuit to achieve broader bandwidths. In this case, the addition of the second tuned circuit will be seen to give much broader bandwidths than one would expect from conventional filter theory. Two sample amplifiers are considered and their bandwidths calculated. The effect of double tuning one of the amplifiers is then considered.     

A Novel Design for Polarization-Independent Single-Pump Fiber-Optic Parametric Amplifiers

We propose a novel scheme for designing fiber-optic parametric amplifiers whose operation does not depend on the input signal polarization. In our scheme, four-wave mixing takes place inside a birefringent fiber pumped at 45deg from a principal axis. We show numerically that output power varies by <0.1 dB for arbitrary states of input polarization under practical conditions     

Design Considerations for an Integrated 1.8-GHz Parametric Amplifier

A hybrid-integrated parametric amplifier has been fabricated in a microstrip transmission-line configuration. General design considerations and their implementation in a microstrip medium are discussed. The amplifier exhibited a power gain of 10 dB and 50-MHz half-power bandwidth with a noise figure of 2.0 dB. It was pumped at X-band frequency and required only 10 mW of pump power. The integrated pump source consisted of the transistor oscillator and a varactor quadrupler stage.     

Design Considerations for an Integrated 1.8-GHz Parametric Amplifier

A hybrid-integrated parametric amplifier has been fabricated in a microstrip transmission-line configuration. General design considerations and their implementation in a microstrip medium are discussed. The amplifier exhibited a power gain of 10 dB and 50-MHz half-power bandwidth with a noise figure of 2.0 dB. It was pumped at X-band frequency and required only 10 mW of pump power.The integrated pump source consisted of the transistor oscillator and a varactor quadruple stage.     

Optimal Design for System Reliability and Maintainability

A complex system consisting of N modules that are logically interconnected for mission success is to be placed in the field for a fixed period of time. For some modules, standby units can be provided, for others this option is not available, but we must select from among several design alternatives differing in cost, weight, and reliability. The problem is to determine simultaneously the module designs and the numbers of standby units to maximize the system reliability, subject to cost and/or weight constraints. Other authors have considered a similar problem for a pure series inter-connection of modules, but we permit the system to be any configuration of modules in series and/or parallel. A dynamic programming model is presented for this problem. The notion of the generalized decomposition operator is used to develop a set of recursive relations. An example is included.     

基于分类可靠性的WDM环网设计

利用分类可靠性概念解决WDM多纤双向环网中的路由和波长分配问题。基于分类可靠性概念和环网的重用保护波长机制,提出了一种改进的最难重用优先算法。利用该算法,可以在满足每个连接可靠性要求的同时,使整个环网所需的波长里程数最小。     

内调制光敏管的可靠性分析和设计

介绍了内调制光敏管的可靠性试验及其失效模式和失效机理的分析。寿命试验结果表明内调制光敏管的平均寿命超过１９４９６小时。     

内调制光敏管的可靠性分析和设计

介绍了内调制光敏管的可靠性试验及其失效模式和失效机理的分析.寿命试验结果表明内调制光敏管的平均寿命超过19496小时.     

星载合成孔径雷达的可靠性设计

阐述了星载合成孔径雷达的可靠性建模、可靠性指标分配和可靠性预计的方法，明确了星载合成孔径雷达的降额设计、热设计、冗余设计、结构设计、软件设计、接口设计、抗干扰设计、环境适应性设计等可靠性设计要求，从而保证了产品可靠性指标的实现。