1、 Microwave Component Mechanics For a listing of recent titles in the Artech House Microwave Library, turn to the back of this book. DISCLAIMER OF WARRANTY The technical descriptions, procedures, and computer programs in this book have been developed with the greatest of care and they have been usefu
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5、ave Component Mechanics Harri Eskelinen Pekka Eskelinen Artech House Boston London Library of Congress Cataloging-in-Publication Data Eskelinen, Harri. Microwave component mechanics/Harri Eskelinen, Pekka Eskelinen. p.cm. (Artech House microwave library) Includes bibliographical references and index
6、. ISBN 1-58053-368-X (alk. paper) 1. Microwave devicesDesign and construction.I. Eskelinen, Pekka.II. Title. III. Series. TK7876.E852003 621.38133dc212002043667 British Library Cataloguing in Publication Data Eskelinen, Harri Microwave component cechanics.(Artech House microwave library) 1. Microwav
7、e devicesDesign and construction I. TitleII. Eskelinen, Pekka 621.3 8133 ISBN 1-58053-368-X Cover design by Igor Valdman 2003 ARTECH HOUSE, INC. 685 Canton Street Norwood, MA 02062 All rights reserved. Printed and bound in the United States of America. No part of this book may be reproduced or utili
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9、ately capitalized. Artech House cannot attest to the accuracy of this informa- tion. Use of a term in this book should not be regarded as affecting the validity of any trade- mark or service mark. International Standard Book Number: 1-58053-368-X Library of Congress Catalog Card Number: 2002043667 1
10、0 9 8 7 6 5 4 3 2 1 Contents Acknowledgmentsxv Introductionxvii Part 1: Design for Manufacturability and Assembly of Mechanical Microwave Components1 1Special Requirements for Microwave Mechanics3 1.1Fundamentals of Microwaves4 1.1.1Maxwells Equations4 1.1.2General Wave Propagation5 1.2Dimensional U
11、ncertainties8 1.3Material Problems15 1.3.1A Good Conductor17 1.3.2Electromagnetic Radiation19 1.3.3Electromagnetic Waves Initiated by Cavities22 1.4Connection Philosophies26 v 1.5Typical User and Application Profiles27 References27 2Systematic Flowchart Model29 2.1Principles of Systematic Design29 2
12、.1.1Some Assisting Tools31 2.1.2List of Requirements33 2.2Advanced Methodology for Designing Microwave Mechanics34 2.2.1Basic Elements of the Advanced Methodology35 2.2.2Flowchart Presentation of the Tuned Methodology39 References42 3Material Selection for Microwave Mechanics45 3.1Basic Guidelines f
13、or Microwave Designers45 3.2Effects of the Products Operating Frequency47 3.2.1Electromagnetic Losses47 3.2.2Definition of the Penetration Depth48 3.3Effects of the Operating Environment51 3.4Metallic Components54 3.4.1Oxygen-Free Copper55 3.4.2Superconductor Oxygen-Free Copper55 3.4.3Beryllium Copp
14、er Alloy56 3.4.4Phosphorus Bronze57 3.4.5Brass58 3.4.6Stainless Steels58 3.4.7Aluminum Alloys60 3.4.8Invar62 3.5Use of Plastics64 3.5.1PTFE64 3.5.2PE64 3.5.3Other Fluorine Plastics65 3.5.4PEEK65 viMicrowave Component Mechanics 3.5.5Polyphenylene Oxide66 3.5.6Reinforced Plastics66 3.6Utilization of C
15、eramic Materials and Powder Metallurgy66 3.6.1Powder-Metallurgically Manufactured Materials for Microwave Mechanics69 3.6.2Application Areas of Ceramic Materials in Microwave Mechanics73 3.6.3Low Temperature Cofired Ceramics74 References77 4Computer-Aided Environment for Design Work79 4.1Integration
16、 of Basic CAD Tools80 4.1.1Interaction Between Virtual Engineering and Hypermedia Applications in Controlling Heat Input During Welding of Microwave Components86 4.1.2Integration of Computer-Assisted Engineering and Microwave Mechanics Simulation in Welded Stripline Filter Design94 4.2Typical Simula
17、tion Software Solutions for Microwaves96 4.3Integration Problems of Current CAD Applications102 4.3.1Problems in CAD Applications Made for General Mechanical Engineering102 4.3.2Problems in CAD Applications Developed for Microwave Design103 References108 5Instructions for Technical Documentation and
18、 Dimensioning111 5.1The Relationship Between RF Parameters and Mechanical Parameters112 5.2Differences Between DFMA- and Performance-Oriented Approaches114 Contentsvii 5.3On the Suitability of General Manufacturing Tolerances for MW Mechanics116 References118 6Effects of Production Volume and Relate
19、d Topics119 6.1General Aspects Related to the Evaluation of Production Costs119 6.1.1Design Costs119 6.1.2Material Costs120 6.1.3Manufacturing Costs120 6.1.4Costs Related to the Expected Lifetime of the Product120 6.2Relationship Between Manufacturing Costs and Surface Finish121 6.3Relationship Betw
20、een Manufacturing Costs and Dimensional Tolerance122 6.4Design for Manufacturability122 6.4.1Goals of DFM/DFMA123 6.4.2The Barrier Between Designing and Manufacturing123 6.4.3Putting DFM in Practice125 6.4.4Additional Tools for DFM127 6.4.5More Effective Use of DFM128 6.5A Cross-Technological Approa
21、ch129 6.6Concurrent Engineering Design131 6.6.1The Design Process for CE132 6.6.2Manufacturability for CE Design133 6.7Manufacturing Costs of Prototypes134 6.8Quality Aspects135 6.9Cost Evaluation by Utilizing Parametric Component Design135 6.10Cost Accumulation in Laser Processed Components136 6.11
22、Manufacturing Costs of Other Manufacturing Processes141 viiiMicrowave Component Mechanics 6.12A Multilevel Optimizing Approach for Cost-Effective Production141 References148 Part 2: Manufacturing Technologies for Some Passive Microwave Components151 7Welded Components153 7.1Welding Processes for the
23、 Topic Area153 7.2Laser Welding in General154 7.2.1Parameters of Laser Welding156 7.3Laser-Welded Stripline Filter157 7.4Utilizing Ultrasonic Welding in Filter Constructions164 7.5Welded Joint Geometries of Microwave Cavity Resonators and Waveguides170 7.5.1Practical Welding Instructions for Cavity
24、Resonators and Waveguides174 7.6Welded Radiating Elements of Patch Antennas177 7.7A Comparison of Welding Processes for Encapsulating Electronics192 7.7.1Advantages of Laser Welded Sealing193 7.7.2Projection Welding Application197 References200 8Other Joining Technologies203 8.1Assembly Rules for Sc
25、rew Joints to Obtain Reliability and Required Microwave Performance203 8.2Glued Joints205 8.2.1Acrylic-Based Adhesives205 8.2.2Cyanoacrylate-Based Adhesives206 8.2.3UV-Cured Adhesives206 8.2.4Adhesives with Good Electrical Conductivity206 Contentsix 8.2.5Adhesives for High-Strength Applications208 8
26、.2.6High-Temperature Ceramic Adhesives209 8.3Applications of Fits209 References210 9Machined Components211 9.1General Rules for Machining Technologies211 9.2Milled Low Loss Filters215 9.3Ring Hybrids and Other Milled Power Dividers218 9.4General Enclosures for Encapsulating Electronics224 9.5Connect
27、or Mounting Considerations229 9.6Rotary Joints231 9.6.1Basic Waveguide Rotary Joints233 9.6.2Swivel Joints234 9.6.3Coaxial Rotary Joints235 9.6.4Dual Channel Rotary Joints235 9.6.5Multichannel Rotary Joints235 9.7Case Examples of Precision Machined Microwave Components237 9.7.1High-Q SiO2Whispering
28、Gallery Mode Resonator238 9.7.2Center Conductor for a Tubular Coaxial Filter239 References240 10Cutting Processes243 10.1Sheet Metal Cutting In General243 10.2Water Jet Cut Striplines and Microstrips246 10.2.1A Water Jet Cut Ring Hybrid246 10.2.2A Water Jet Cut Stripline Feeding Network249 10.3Laser
29、 Processed Feeding Strips249 10.3.1Laser Cutting Process in General250 10.3.2A Laser Cut Sharp-Edged Center Conductor251 xMicrowave Component Mechanics 10.3.3Laser Cut Striplines for Low-Loss Interdigital Filters253 10.4Tuning Coaxial Transitions256 References259 11Forming Processes261 11.1Extrusion
30、 Processes for Metallic Profiles261 11.2Selected Processes for Shaping Plastics264 11.2.1Injection Molding265 11.3Drawing Processes for Wires266 11.4Forming Processes for Sheet Metals267 11.5Electroforming Process for Corrugated Waveguides268 References269 12Coating271 12.1Basics of Coating Technolo
31、gy271 12.2Requirements for Coating Quality273 12.3Coating Materials for Microwave Mechanics273 12.4Case Examples of Coated Microwave Components278 References282 Part 3: Examples of Requirements for Mechanical Accessories in Microwave Assemblies283 13A Microwave Measuring System for Wood Quality285 1
32、3.1Description of the Test Arrangement286 13.2Transducer Arrangements289 13.3Mechanical Requirements for the Measurement System Assembly291 13.3.1Serviceability and Easy Access293 References294 Contentsxi 14Antenna Constructions295 14.1Basis for the Design of Antenna Constructions296 14.2Wind and Ic
33、e Loads297 References300 Part 4: Test Arrangements and Results of Microwave Components Manufactured with Alternative Technologies301 15Mechanical Measuring Equipment303 15.1Dimensional Uncertainties303 15.1.1Measuring Dimensional Uncertainties303 15.1.2Measuring Geometric Tolerances304 15.2Joint Rel
34、iability310 15.3Surface Properties310 15.3.1Oxide Layers311 15.3.2Surface Defects Caused During Manufacturing Processes311 15.3.3Mechanical Composition of the Surface Texture312 15.3.4Measuring Surface Roughness313 15.3.5Friction Measurement315 15.3.6Wear Measurement315 15.3.7Hardness Tests317 15.4T
35、ests for Hermetic Enclosures317 References318 16Selecting Microwave Test Instrumentation321 16.1Vector Network Analyzers322 16.2Spectrum Analyzers323 16.3Signal Generators324 16.4Cables, Connectors, and Some Accessories325 References325 xiiMicrowave Component Mechanics 17Examples of Practical Test S
36、et-Ups327 17.1Passive Intermodulation in Welded Components327 17.2Testing the Shielding Performance of Microwave Enclosures329 17.3Experiments on the Input Impedance of Waveguide to Coax Transitions330 17.4Analyzing the Effects of Mechanical Defects on the Performance of Small Phased Array Antennas3
37、32 References338 18Summary339 List of Acronyms343 List of Symbols349 Requirements for Viewing Appendixes A, B, and C353 About the Authors355 Index357 Contentsxiii . Acknowledgments Many of the results and ideas presented in this book have been collected over the past 3 years during several projects
38、in which other people have participated. The authors want to gratefully acknowledge Jussi for the technical help and support in computer graphics and e-mail handling. Without his magic tricks, there would be very few illustrations to support the text. Jouni and his skilled team in the workshop made
39、excellent prototypes of selected designs. Special thanks are also given to the anonymous reviewer of the publisher, Artech House, for the careful and detailed suggestions that have improved the accuracy and readability of this book. Senior commissioning editor, Dr. Julie Lancashire stabilized the at
40、mosphere for fruitful discussions. Pekka is deeply impressed by Tuulas care-taking and loving attitude through all the years. Harri wants to give a big hug to his three beautiful cocker spaniels Nome, Taika, and Petra for their patience in waiting their turn every evening during the long writing pro
41、cess. Finally, the authors want to remember their late father, who gave us both the spirit and opportunity to engage in technical experiments and hard work. xv . Introduction Microwaves are generally considered to be a specific part of the wide radio frequency spectrum. The band from 300 MHz to 30 G
42、Hz is typically con- sidered to be “microwaves,” for example by the Institute of Electrical end Electronics Engineers (IEEE), although many of us prefer to set the lower limit somewhat higherperhaps at 1 or even 3 GHz. Above 30 GHz, the term “millimeter waves” is used. High school physics suggests t
43、hat we are talking about wavelengths ranging from about 30 cm down to 10 mm. The tremendous growth in mobile communications during the past 10 years has particularly caused a respective increase in the need for micro- wave and millimeter wave components, devices, and systems. Besides this well-known
44、 application area, microwave frequencies are widely in use, for example, in satellite networks, radar and navigation systems, remote sensing, and industrial measurements. Two common features are seen in the latest developments. First, the number of individual units (components or devices) is increas
45、ing exponentially, so their production costs should be minimal. At the same time, many of the technical requirements, especially those related to microwave performance, are becoming more and more strict. Higher power levels and lower noise figures should be available, and systems should with- stand
46、considerable amounts of mutual interference without noticeable degra- dation in service quality. In addition to this, weight and size constraints are becoming severe. In the early days of microwave engineering (back in the 1930s and 1940s), most components were manufactured as highly precise mechani
47、cal xvii elements. This was mandatory, because no semiconductor processes were available nor were there any practical planar circuit board technologies at hand for industrial-scale work. Active devices were mostly electron tubes, which, as such, required the extreme capabilities of the mechanical wo
48、rk- shop. Modern microwave components can make use of highly sophisticated semiconductor designs. Miniature-scale planar circuits enable the integration of complete transceivers, such as automobile anticollision radars, into enclo- sures that are hardly larger than common microwave connectors. The u
49、se of mechanical structures, however, will continue. Their necessity as a practical interface between the planar circuits and the macroscopic “real” world is even greater. Devices which call for the lowest loss or which have to handle very high power levels, may well also be “classical” all-metallic components in the future. As long as microwave devices (such as amplifiers, filters, and detec- tors) are sold as separate items for system integration or prototyping, there will be connectors, waveguide flanges, and a need for microwave mecha
