Agilent Technologies 4395A - Page 297

AM
Signal
Measurement
(SA)
Figure
10-17.
Carrier
Amplitude
and
Frequency
of
AM
Signal
The marker
shows
that
the
carrier
amplitude
(
E
c
)is
0
20.305
dBm
and
frequency
(
f
c
)is
100
MHz.
Modulating
Frequency
and
Modulation
Index
Measurement
Using
1Marker
3.
Press
4
Ma
rk
er
5
N
N
N
N
N
N
NN
NN
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
1MODE
MENU
N
N
N
N
N
N
NN
NN
N
N
N
N
1MKR
.
4.
Press
4
Sea
rch
5
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
NN
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
SEARCH:
PEAK
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
NN
N
N
N
N
N
N
N
N
N
N
NEXT
PEAK
to
search
for
a
sideband.
The
oset
value
from
the
carrier
is
displayed
as
the
marker
sweep parameter
value
shown
in
Figure
10-18
.
This
value
is
the
modulation
frequency
.
Figure 10-18. Modulating Frequency of AM Signal
The 1marker shows that the sideband amplitude value relative to the carrier is 0 19.708 dB (see
Figure 10-18). The modulation index ( m ) can be derived from the following equation:
m =2 2 10
1 Mkr
20
=20 : 68%
Examples of Applications 10-19