User`s guide
//
1
II
/
1
/
1
CENTER
400
0
MHZ
CENTER
400
0
MHZ
SPAiN
200
SPAiN
200
.o
MHZ
.o
MHZ
RES
BW
1
0
MHZRES
BW
1
0
MHZ
“BW
300
kHZ
“BW
300
kHZ
SWP
20
SWP
20
0
nl5P
0
nl5P
Figure 3-22.
Figure 3-22. RF
RF
AttenuationAttenuation of 10
of 10
dB
dB
6. Compare the response in trace A to the response in trace B. If the distortion product
decreases as the attenuation increases, distortion products are caused by the spectrum
analyzer input mixer.
Note
When the source signal amplitude is changed between trace A and trace B and
there is a resulting change in the distortion product, this is shown by a change
in the marker amplitude (marker-delta value). An example of the marker-delta
value produced by a change in the distortion product is shown in Figure 3-22.
A change in the distortion product is indicative of high-level input signals
causing circuit overload conditions and producing distortion. This distortion is a
function of the internal hardware of the analyzer. The input signals must be
attenuated to eliminate the interference caused by the internal distortion.
However, if is no change in the distortion product with an increase in
attenuation, the distortion is not caused internally but is a result of distortion
that is present on the input signal as supplied from the signal source. An
example of this is shown in Figure 3-23, where the source signal is not high
enough to cause internal distortion in the spectrum analyzer, therefore, any
distortion that is displayed is present on the input signal.
08
hp
52:
39
APR
07.
1943
MKR
a 0
HZ
HEF
-10
0
dBm
iiAT
10 dR
.c7
dB
PEAK
LOG
10
c1
B
/
CENTER
a00
0
MHZ SPA!4
200
0
MHZ
RES
BW
1.0
MHZ VBW
300
kHL
SW
20
0 nl5e
Figure 3-23. No Harmonic Distortion
Making Basic Measurements
3-21