军用电路板的一种防护方法

军用电子装备使用条件恶劣,对质量与可靠性要求高,为满足战备需求,提高装备的环境适应性能力,必须加强装备的防护能力建设.通过对电子装备核心基础部件印制电路板的防护设计实施和检验,探索出一种适应装备多品种小批量特点,手工实施印制电路板的防护涂覆,通过了环境测试和实际环境验证,是一种有效的印制电路板防护方法.     

宽带平面Balun偶极子天线的FDTD分析

研究了应用时域有限差分法（FDTD）方法分析了平面了Balun偶极子天线。结果表明，FDTD方法分析平面结构的天线非常有效。通过计算，可以得到天线的回波损耗和辐射特性，同时与实验结果相比，具有较好的一致性，对于天线的分析与优化设计具有一定的指导意义。     

WLAN平面天线研究

对一种小型的平面倒F天线进行了研究,根据WLAN 802.11b/g无线通信的需求设计出一种工作于ISM 2.4 GHz频段的小型平面倒F天线。该天线面积小,约为13.5 mm×5.5 mm,能方便地集成在Cardbus卡上,降低射频前端的成本。天线的设计采用了Agilent的ADS2004仿真工具,并给出了该天线的测试方法以及测试结果。     

一种复合巴伦功分器电路的设计

为实现多模信号合成输出,设计了一种复合巴伦功分器电路.文中分析了双层带状线结构,推导出了其特性阻抗计算公式和复合电路的传输矩阵.仿真和测试结果表明,电路具有较好的双模平衡合成性能,同时次模的两个输出实现了180°相移,并在塔康相控阵天线中得到了成功应用.     

Robustness of Printed Patch Antennas

We address the question of robustness of damaged microstrip antennas, the damage being either penetrating, caused by fragment impact, or floating, caused by manufacturing imperfections. A simple analytic expression is derived to facilitate the prediction of robustness. To verify this expression a Monte Carlo method, based on a general 3D electromagnetic solver, is used to evaluate the robustness of the antennas. The simulations are verified by measurements and supplementary simulations in an alternative electromagnetic solver, using the finite difference time domain method (FDTD). The agreement between the simulated results and the analytic expression is found to be good in a qualitative comparison.     

24 GHz On-Chip Antennas and Balun on Bulk Si for Air Transmission

The conditions are investigated under which standard digital bulk Si technology can yield efficient on-chip antennas and baluns for fully differential transmitter and receiver implementations. The effects of the IC material properties and the antenna geometry on radiation and impedance characteristics have been studied. 24 GHz on-chip antennas on lossy Si have been successfully demonstrated, using a standard IC fabrication compatible Cu process. The fabricated antennas demonstrate a gain ranging from 8- to - 10.5 dBi, which is to the best of the author's knowledge, the highest gain reported for antennas in a 10 Omega-cm Si substrate to date.     

Ultrawideband Printed Elliptical Monopole Antennas

Parametric study of ultrawideband printed elliptical monopole antennas have been presented. Design curve for the length of the feed transmission line for various lower band edge frequencies has been generated. Variation of bandwidth with ellipticity ratio of these configurations has also been studied. Experiments have been performed to measure bandwidth and radiation patterns of these configurations, which tally well with simulated results. The elliptical configuration with ellipticity ratio of 1.1 gives ultrawide impedance bandwidth ratio of 12.4:1 as compared to 10.2:1 of the circular monopole antenna. This antenna introduces minimum ringing and distortion/dispersion of the pulse in time domain     

Design of Printed Resonant Antennas for Monolithic-Diode Detectors

Model experiments at 10-GHz band have been performed to obtain optimum structures of printed resonant antennas for monolithic GaAs Schottky-diode detectors in the submillimeter-wave region. Design charts for antenna structures, which are also useful for a thin-film metal-to-metal diode structure on a dielectric substrate, are presented.     

一种采用印制线巴伦技术的1kW高功率放大器

介绍了一种P波段1kW微波脉冲功率放大器.功率合成方式采用印制线巴伦,从理论上简单地分析了这种印制线巴伦功率合成技术,阐述了印制线巴伦的应用,并将其实用化.功率器件采用的是具有高增益特性的功率LDMOS器件,实现了该放大器的高增益设计.这种放大器有效地降低了高功率、高增益放大器的尺寸和成本,功放功率大于900 W,增益大于20 dB,尺寸≤222 mm×82 mm×20 mm.     

印刷环天线的谐振特性

本文基于环形几何上的超二次曲线表示,分析一组印刷环天线的谐振特性,首先给出求解天线电流分布和辐射场的统一数值计算公式,然后通过改变超二次曲线的开头参数,分析印刷在不同介质基片上环形天线的形状与其谐振电阻和谐振环周长的关系。结果表明,可以通过调整环形天线的几何形状获得与馈线相匹配的谐振电阻。     

Substrate Optimization for Integrated Circuit Antennas

The reciprocity theorem and integral equation techniques are employed to determine the properties of integrated-circuit antennas. The effect of surface waves is considered for dipole and slot elements on substrates. The radiation and bandwidth of microstrip dipoles are optimized in terms of substrate thickness and permittivity.     

A Printed Circuit Stub Tuner for Microwave Integrated Circuits

A novel microwave tuning eIement capable of continuous adjustment has been realized in the form of a planar printed circuit. As such, it is suitable for incorporation into microwave integrated circuits (MIC's), where it can be used for fine-tuning the impedance match between two parts of a circuit when the two parts are either subject to variations due to manufacturing tolerances or are difficult to model. In either case, the tuner is a compact on-circuit tuning facility which does not have to be removed after use. The tuner has been shown to have unique impedance-transforming properties, being capable of matching any realizable impedance to a 50-Omega load. Its main part consists of a coupled-line section and across the gap in the sectiou at different places along its length are positioned two short-circuit bridge conductors. Movement of these bridges produces the variation in impedance transfomration.     

导电胶在印制电路板中的应用

本文介绍了导电胶的组成和特点及其在印制板中的应用,如用于在多层板内层埋入电阻,多层板层间互连,在底板上印刷线路等.阐述了银导电胶和铜导电胶在印制电路板应用中各自的优缺点及其应用的可能性.     

A Novel Technique for Open-Stopband Suppression in 1-D Periodic Printed Leaky-Wave Antennas

A novel technique for the elimination of the open stopband in one-dimensional periodic printed leaky-wave antennas is presented. A quarter-wave transformer, or alternatively a matching stub, is introduced into the unit cell of the antenna, which forces the Bloch-wave impedance of the structure to remain real and non-zero at broadside. The effectiveness of the proposed technique is first demonstrated on a printed periodic microstrip leaky-wave antenna consisting of a single radiating stub per unit cell, which exhibits a significant stopband at broadside. The technique is then also applied to a structure consisting of two radiating stubs per unit cell, which is capable of mitigating, but not eliminating, the open stopband. In both cases the open stopband at broadside is completely suppressed.      

挠性板用阻焊剂

概述了挠性板用阻焊剂的特性和用途,适用于取代保护FPC导体的传统的保护涂覆膜。     

面向当今封装的挠性印制电路板

挠性电路的特征适合于元件之间要求高密度互连的应用,其安装和连接的挠性特征,高密度电路的精确能力,耐热性能,电路终端选择的多样性以及材料和空间的有效使用等使挠性电路在当前和未来的封装应用中具有广阔的应用前景。     

System and Circuit Models for Microwave Antennas

This paper describes how circuit and system models are derived for antennas from measurement of the input reflection coefficient. Circuit models are used to optimize the antenna performance and to calculate the radiated power and the transfer function of the antenna. System models are then derived for transmitting and receiving antennas. The most important contribution of this study is to show how microwave structures can be integrated into the simulation of digital communication systems. This enables system designers to predict the effect of the microwave subsystem on the digital signals and calculate the resulting bit error rate     

印制电路组件的清洗工艺

焊接是电子设备的生产中重要的步骤,焊接后必须进行清洗才能保证电子设备的可靠性、电气指标和工作寿命。鉴于军工产品必须要清洗,所以清洗工艺对于军工产品尤为重要。介绍了清洗的重要性,讨论了印制电路组件污染物的种类、来源分析及相关清洗工艺,并简单介绍了清洗后洁净度的相关检测标准。同时结合自身工作对印制板电路组件焊接后的清洗问题进行了分析,并提出了可靠的解决方案和新的思路。     

Surface Resistivity Characterization of New Printed Circuit Board Materials for Use in Spacecraft Electronics

New dielectric materials have been introduced for printed circuit board applications, such as Thermount and polyimide with the aim to match the requirements for high speed and high density of electronic devices that are planned for new spacecraft electronic boards. Before these newer substrate can fully replace the well-known space-approved material epoxy FR-4, it is necessary to investigate more deeply their electrical and mechanical properties. The scope of this study is to report quantitative characterization of the surface resistivity for the different material samples under various testing conditions that include relative humidity, temperature, solder flux contamination, and corona discharge. The surface resistivity results are reported for sets of samples measured under a combination of testing conditions.     

PCB的激光钻孔技术

概述了PCB激光钻孔技术的现状和下一代PCB激光钻孔技术的动向。