Rf communication and signals experiments – GW Instek GRF-1300A User Manual

Page 77

RF Communication and Signals Experiments

Step1

Step2

Step3

Step4

4. Use the Marker function on the spectrum analyzer and measure

the carrier position at this time.

Step5

5. Turn the potentiometer clockwise to an arbitrary position.

Measure the voltage with an oscilloscope. Does the FM wave
spectrum change after the output amplitude of the modulating
signal has changed? Follow the steps below to measure the
frequency deviation and record it in Table 6-2.

Step6

Marker

6. Turn the potentiometer clockwise again to a different position.

Measure the voltage with an oscilloscope. Does the spectrum of
the FM wave change when the output amplitude of modulating
signal changes? Follow the steps below to measure the frequency
deviation and record it in Table 6-2.

Step7

7. Adjust the potentiometer to the maximum position. Repeat the

above steps and record the results in Table 6-2.

Step8

8. After the completing the experiment steps above, see if there is

any change to the spectrum of the FM wave when the UP button
on the baseband module is used to change the frequency of the
modulating signal. Compare this to the original 100kHz
baseband signal and record it to Table 6-3.

Step9

9. Change the modulating signal frequency to 600KHz. Observe the

change in the spectrum of the FM wave and record the results in
Table 6-3.