BASIC RADAR SYSTEMS
Upon completing this chapter, you should be able to do the
1. Describe the two types of energy transmission used by radar
2. Describe the different seaming techiques used in radar systems.
3. Describe the major components in todays radar transmitters.
4. List the basic design requirements of an effective radar receiver.
Basic Pulse-Radar System
The two basic types of radar systems, pulse radars
and continuous-wave radars, use pulse and contin-
uous-wave energy transmission. As a Fire Control-
man, you need to know how these systems work. This
chapter discusses radars, scanning methods, transmit-
ters, and receivers in detail.
For further information on radar systems, refer to
Microwave Principles, Module 11, Navy Electricity
and Electronics Training Series, NAVEDTRA 172-
11-00-87; and Radar Principles, Module 18, Navy
Electricity and Electronics Training Series, NAVED-
This section discusses the two types of pulse
radars and the two types of continuous-wave radars.
The pulse-radar systems include
radar and the pulse-Doppler radar.
The signal of a basic pulse-radar system is gen-
erated by the transmitter and is radiated into space by
the antenna. Intermediate frequencies from 30 to 60
MHz are commonly used because signal handling is
easier to accomplish at the lower frequencies than at
the transmitter frequencies.
The duplexer enables the use of a single antenna
to transmit and receive the radar signal. The return
echo signal is then mixed with a local oscillator (LO)
signal to produce an intermediate frequency (IF)
signal at a lower frequency than the transmitter.
The IF filter conditions the echo signal through
amplifying and filtering extraneous signals. The IF
signal is then sent to the second detector where the IF
is converted to a lower frequency video signal. At that
time, the video signal is processed for display by a
The display is usually a cathode-ray tube (CRT)
the basic pulse
that is monitored by an operator. The timer/synchro-
nizer controls the repetition frequency of the trans-