Atec Rohde-Schwarz-SMF100A - Manual (Page 10)

The ¸SMF100A in the "FM-modulated noise" application
A
Ref 10 dBm Att 35 dB
1 SA
AVG
Center 5 GHz Span 2 MHz 200 kHz/
RBW 50 kHz
VBW 200 kHz
SWT 20 ms
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
A
Ref 10 dBm Att 35 dB
1 SA
AVG
Center 5 GHz Span 2 MHz 200 kHz/
RBW 50 kHz
VBW 200 kHz
SWT 20 ms
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
A
Ref 10 dBm Att 35 dB
1 SA
AVG
Center 5 GHz Span 2 MHz 200 kHz/
RBW 50 kHz
VBW 200 kHz
SWT 20 ms
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
CW
10 ¸SMF100A Microwave Signal Generator
LO with exceptionally low
SSB phase noise
Because of its very low SSB phase noise,
the ¸SMF100A can be used for a
wide variety of applications. However,
there are applications that require
"worse" SSB phase noise for testing.
For these cases, the ¸SMF100A
offers a unique function: FM-modulated
noise enables you to artificially degrade
the instrument's low SSB phase noise in
order to test the response of an oscillator
or synthesizer, for example. The figure shows an unmodulated CW
signal and a signal that is FM-modulated
with noise. By varying the FM deviation,
you can degrade the SSB phase noise.
The figure on the right shows the com-
pensated frequency response of the am-
plifier with activated "User correction"
(straight line at 5.7 dBm starting at
2.5 GHz up to 3.5 GHz). This procedure
ensures that only the frequency response
of a bandpass filter is measured, for
example, but not the combined frequency
response of amplifier and bandpass.
Output characteristic of an amplifier obtained by applying “User Correction”, with the ¸SMF-K28
power analysis option installed.
SMF_bro_en_5213-7660-12_v0201.indd 10 13.02.2009 15:44:21