Programmed Review for Electrical Engineering, Third Edition
This text contains an organized review of the basic electrical engineering fundamentals, with 111 problems, solutions and explanations for the core electrical engineering concepts.
TABLE OF CONTENTS Programmed Review for Electrical Engineering, Third Edition
Chapter 7: Communications
Discussion of and problems related to low-frequency transmission, RF transmission, and attenuation.
Introduction
This chapter deals with communications problems that fall into either of two frequency bands: low frequency or radio frequency. The low-frequency band is generally that range between 500 Hz and 1 MHz; this includes telephone transmission problems. The RF range is considered to be anything above 1 MHz; this includes radio and television broadcasting, antennas, and waveguides.
Each band has its own transmission line characteristics, permitting certain unique assumptions to be made.
Low-Frequency Transmission
In this section, the transmission line is treated as a circuit having distributed parameters defined below:
| R | = | series resistance, ohms per unit length of line (includes both wires) |
| L | = | series inductance, henries per unit length of line |
| C | = | capacitance between conductors, farads per unit length of line |
| G | = | shunt leakage conductance between conductors, mhos per unit length of line |
| ?L | = | series reactance, ohms per unit length of line |
| Z | = | R + j ?L = series impedance, ohms per unit length of line |
| ? C | = | shunt susceptance, mhos per unit length of line |
| | ||
| Y | = | G + j ?C = shunt admittance, mhos per unit length of line |
| s | = | distance to point of observation, measured from receiving (or sending) end of the line |
| I | = | current at any point in the line |
| E | = | voltage between the conductors at any point |
| l | = | length of the line |
| ? | = |
Copyright Dearborn Financial Publishing, Inc. 2004 under license agreement with Books24x7
