常用参数等Radio-Frequency and Microwave Communication Circuits: Analysis and Design Devendra K. Misra Copyright # 2001 John Wiley & Sons, Inc. ISBNs: 0-471-41253-8 (Hardback); 0-471-22435-9 (Electronic) APPENDIX 2 CHARACTERISTICS OF SELECTED TRANSMISSION LINES COAXIAL LINE Consider a coaxial line with its inner and outer conductor radii a and b, respectively, as illustrated in Figure A2.1. Further, er is the dielectric constant of insulating material. The line parameters L, R, C, and G of this coaxial line are found as follows: C and, L 200 lnb=a nH=m A2:2 55:63er lnb=a pF=m A2:1 If the coaxial line has small losses due to imperfect conductor and insulator, its resistance and conductance parameters can be calculated as follows: 1 1 R % 10 a b and, G 0:3495er fGHz tand lnb=a S=m A2:4 553 r fG……