User's Guide

Appendix A. Radio Signal Propagation
BreezeNET BU-DS.11/RB-DS.11 A-1 User’s Guide
APPENDIX A. RADIO SIGNAL PROPAGATION
A.1 Radio Signal Propagation
A.1.1 Introduction
This section explains and simplifies many of the terms relating to antennas and RF (Radio
Frequency) used when dealing with an RF installation system.
The following diagram depicts a typical radio system:
Figure A-1. A Typical Radio System
A radio system transmits information to the transmitter. The information is transmitted through an
antenna which converts the RF signal into an electromagnetic wave. The transmission medium for
electromagnetic wave propagation is free space.
The electromagnetic wave is intercepted by the receiving antenna which converts it back to an RF
signal. Ideally, this RF signal is the same as that originally generated by the transmitter. The original
information is then demodulated back to its original form.
A.1.2 RF Terms and Definitions
dB
The dB convention is an abbreviation for decibels. It shows the relationship between two values.
RF Power Level
RF power level at either the transmitter output or the receiver input is expressed in Watts. It can
also be expressed in dBm. The relation between dBm and Watts can be expressed as follows: