
SC5305A Operating & Programming Manual
54
Figure 8. Plots show the raw spectral purity for a 100 MHz input RF signal (LO = 4.775 GHz). Note that the power
supply noise of 60 Hz and its harmonics are in the noise. The measurement instrument is not phase-locked to
the unit under test.
-120
-100
-80
-60
-40
-20
0
-5
-3
-1
1
3
5
dB
c
Frequency offset (MHz)
100 MHz carrier
10 MHz span
-100
-80
-60
-40
-20
0
-100
-50
0
50
100
dB
c
Offset Frequency (kHz)
100 MHz carrier
200 kHz span
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
dBc
Offset Frequency (kHz)
100 MHz Carrier
1 kHz span