Agilent Technologies Agilent 4396B - Manual (Page 79)

Figure 4-12. Carrier Amplitude and Frequency of AM Signal
The marker shows that the carrier amplitude (E c ) is 019.949 dBm and
frequency (f c ) is 100 MHz.
Modulating Frequency and Modulation Index Measurement Using 1Marker
3.
Press 4 Ma rk er 5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
1MODE MENU
NNNNNNNNNNNNNN
1MKR .
4.
Press 4 Search 5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
SEARCH:PEAK
NNNNNNNNNNNNNNNNNNNNNNNNNNNNN
NEXT PEAK to search for a sideband.
The oset value from the carrier is displayed as the marker
sweep parameter value shown in Figure 4-13. This value is the
modulation frequency .
Figure 4-13. Modulating Frequency of AM Signal
The 1marker shows that the sideband amplitude value relative to the
carrier is 019.76 dB . The modulation index (m) can be derived from
the following equation:
m = 10
1 Mkr+6
20
= 20: 51%
where 1Mkr is the 1marker sweep parameter value shown in
Figure 4-13.
Spectrum Measurement Examples 4-11