All RF Cafe quizzes make great fodder
employment interviews for technicians or engineers - particularly those who are fresh
out of school or are relatively new to the work world. Come to think of it, they would
make equally excellent study material for the same persons who are going to be interviewed
for a job.
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RF Cafe Quizzes.
Note: Some material based on books have quoted passages.
This quiz is based on the information presented
Introduction to Airborne Radar, Third Edition, by Hugh D. Griffiths, Christopher Baker, and David Adamy.
The publisher was not kidding when he stated, "recognizing that people who have an interest in airborne radars love airplanes, dispersed
through the book are photos and renderings of radar-bearing aircraft from all over the world." If for no other reason, Stimson's book is
a good one to leave on your desk or coffee table as a way-cool picture book for your friends to peruse while visiting. Introduction to
Airborne Radar is in every sense a text designed to turn the electronics neophyte who has a reasonable grasp of algebra and physics
into a technician who possesses a working knowledge of airborne radar (and radar in general) transmitter, receiver, antenna, and processor
systems. The authors teach from first principles about antenna radiation, the decibel, frequency conversion, filtering, signal processing,
target acquisition and tracking, spread spectrum, Doppler shift, radar cross section, electronic countermeasures,
clutter cancelling, platform configurations, and much more. This book is not like the equally
Radar Handbook that is chock full of equations and theoretical discussions, known to make otherwise competent technophiles
curl into a prenatal position while rocking back and forth. It is impossible for a reader to study this entire book and not be able to participate
in an intelligent conversation on radar systems from both a technical standpoint and a historical perspective. Can you tell I'm impressed?
Note: Some of these books are available as prizes in the monthly RF Cafe
Giveaway; however, this one will likely remain in my possession for a long time..
1. What is another, more common name for a coherent radar system?
a) Linear frequency radar
b) Linear phase radar
c) Pulse Doppler radar
d) Constant amplitude radar
2. Match the following common radar frequency bands with their central frequencies.
3. In which direction(s) does(do) an antenna's sidelobe(s) exist?
a) Front only
b) Side only
c) Back only
d) All directions
4. What causes a grating lobe in an electronically scanned antenna?
a) Spacing radiating elements at too great of a distance
b) Spacing radiating elements at too small of a distance
Too low radiated power
d) Too high radiated power
5. What is the main advantage of a pulsed radar over a non-pulsed radar?
a) Pulsed radar avoids transmitter leakage issues
b) Pulsed radar allows higher power
c) Pulsed radar is less
expensive that non-pulsed radar
d) Pulsed radar can be used on airborne platforms whereas non-pulsed cannot
6. What is radar cross-section (RCS)?
a) Physical size of the radar unit
b) Physical size of the radar antenna
c) Effective size of the radar unit and
antenna relative to a perfect radar system
d) Effective area of the signal reflecting surface relative to a perfectly reflecting
sphere of the same projected area
7. What is "chirping?"
a) Linear amplitude modulation over the transmit time
b) Linear frequency modulation over the transmit time
Transmitting one under PAR
d) Radar return of a flock of birds
8. Coherence in radar refers to which of the following?
a) Time of the signal from one pulse to the next
b) Frequency of the signal from one pulse to the next
of the signal from one pulse to the next
d) Phase of the signal from one pulse to the next
9. What defines bins in a Doppler filter bank?
a) Frequency bands
b) Amplitude ranges
c) Time segments
d) Phase angles
10. What is the name for unwanted returns from the ground?
c) Specular ambiguity
d) Frequency inversion
11. Match each picture with what it represents.
12. Which type of pulse repetition frequency (PRF) results in unambiguous range?
d) All three
Need some help?
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