Chapter 1. Introduction

Chapter 1. Introduction
As a result of rapidly advancement in
communication technology, all the mobile technology of
applications has significantly and profoundly influenced
our lifestyle since military began to adopt the traditional
communication system in World War II. To implement the
relevant scientific theory and engineering basis, all need
to resort to fulfilling the RF signal measurement to attain
the desired achievements in communication. This
application note is intentionally provided as an entrance
to comprehend on spectrum analyzer. This kind of
analyzer can be characterized as the roles proximal to
frequency counter and power meter calibrated to the RMS
value of a sinusoidal waveform. Actually, it is worthwhile
emphasizing that spectrum analyzer can behave as the
functions more than frequency counter and power meter
do in many aspects of complicated measurements.

What measurement information comes from a spectrum
analysis?
In order to smoothly proceed in practical
measurement work for a RF signal, it is necessary for an
engineer to understand notions of the spectrum before
touching operation principle of spectrum analyzer at the
first time. As an ubiquitous phenomenon existing around
this physical world to know about distribution of the
signal with different frequencies, we often inspect events
of the signal waveform from time horizon on an
oscilloscope screen. Thus, an oscilloscope can act as a
measurement device to capture any instantaneous
physical state of the desired waveform. The genetic
development of spectrum analyzer is from the precedent
experiment relevant to measuring the frequency for
communication system in signal detection with frequency
domain. Since then, measurements in frequency domain