Chapter 2. Introduction

facilitate to develop this kind of analyzer in acquiring
various parameters of modern communication systems,
including average noise level, dynamic range, and
frequency range, and so on. Besides, the measurements
in time domain also enable the functions to achieve the
transmitted output power. Therefore, in aspect to
measurement function, spectrum analyzer perform
superior to frequency counter, power meter, and
traditional frequency analyzer.

Fig.1. A complex signal analysis proceeds in time
domain, for example, square wave
It is important for RF engineers to require
information mining for detailed analysis from the
measurement in frequency domain, although inspecting
waveform state of a signal can be easily gained from a
traditional oscilloscope.
Using oscilloscope to characterize the whole picture
for waveform state of a signal can be insufficient for
further diagnosis, as a desired signal is often composed
of the various component signals. Any waveform state of
a signal event in time domain consists of many
component signals which can be sine wave with
associated frequency, amplitude, and phase.