Rohde & Schwarz R&S FSP Series, Руководство по эксплуатации

Страница: 56 / 796

R&S FSP Getting Started
Measurements on Modulated Signals
2.32 Operating Manual 1164.4556.12 - 06
Fig. 2-2 Repeatability of adjacent channel power measurement on IS95-standard
signals if the integration bandwidth method is used
6. Switch to Fast ACP to increase the repeatability of results.
➢
Press the CP/ACP CONFIG ! softkey.
➢
Set the FAST ACP softkey to ON .
➢
Press the ADJUST REF LVL softkey.
The R&S FSP measures the power of each channel in the time domain. The
trace represents power as a function of time for each channel (see
Fig. 2-3 ).
The numerical results over consecutive measurements become much more
stable.
Fig. 2-3 Measuring the channel power and adjacent channel power ratio for IS95
signals in the time domain (Fast ACP)
The following figure shows the repeatability of power measurements in the
transmit channel and of relative power measurements in the adjacent channels
as a function of sweep time. The standard deviation of measurement results is
calculated from 100 consecutive measurements as shown in
Fig. 2-2 . Take
scaling into account if comparing power values.
ACPR Repeatability IS95
IBW Method
0
0,2
0,4
0,6
0,8
1
1,2
1,4
10 100 1000
Sweep time/ms
S
tan
dar
d de
v /
d
B
Adjacent channels
Alternate channels
Tx channel