16.
The purpose of using feedback in the demodulation process is to provide a means of satisfactorily
demodulating signals that have
a.
high threshold levels.
b.
high signal-to-noise ratios.
c.
low carrier-to-noise ratios.
d.
a constant intermediate frequency.
17.
The demodulator circuit that causes the receiver's bandpass to appear narrower to signals with high-noise
content than to signals with low-noise content is called an
a.
AFC circuit.
c.
AMFB circuit.
b.
AGC circuit.
d.
FMFB circuit.
18.
The purpose of automatic frequency control in a receiver is to insure that
a.
the average IF is constant.
b.
a maximum IF deviation is achieved.
c.
a minimum IF deviation is achieved.
d.
the IF signal amplitude is constant.
19.
When the IF signal in a receiver is in phase with the reference oscillator's signal, what is the output of the
phase detector?
a.
Zero
c.
Negative
b.
Positive
d.
Alternating
20.
How many conversion stages are used in the signal path of the FMFB receiver shown in figure 115?
SITUATION:
Assume that the simplified block diagram shown in figure 115 represents a receiver used in a microwave
communication system. You must orient yourself with the purposes and uses of each stage in the receiver.
344 L3
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