R&S FSQ Signal Analyzer - Rohde & Schwarz

R&S FSQ Getting Started
Measurements on Modulated Signals
There are two possible methods for measuring channel and adjacent channel power
with a Signal Analyzer:
The IBW method (Integration Bandwidth Method) in which the R&S FSQ measures
with a resolution bandwidth that is less than the channel bandwidth and integrates
the level values of the trace versus the channel bandwidth. This method is described
in section “Noise Measurements” on page 2.17
Measurement using a channel filter.
In this case, the R&S FSQ makes measurements in the time domain using an IF filter
that corresponds to the channel bandwidth. The power is measured at the output
of the IF filter. Until now, this method has not been used for Signal Analyzers,
because channel filters were not available and the resolution bandwidths, optimized
for the sweep, did not have a sufficient selectivity. The method was reserved for special
receivers optimized for a particular transmission method.
The R&S FSQ has test routines for simple channel and adjacent channel power
measurements. These routines give quick results without any complex or tedious
setting procedures.
2.5.3.1 Measurement Example 1 – ACPR Measurement on an IS95 CDMA Signal
Test setup
Settings on the signal generator (e.g. R&S SMIQ)
Frequency: 850 MHz
Level: 0 dBm
Modulation: CDMA IS 95
Measurement with the R&S FSQ
1. Set the R&S FSQ to the analyzer mode.
➢ Press the SPECTRUM key.
The R&S FSQ is in the analyzer mode.
2. Set the center frequency to 850 MHz and frequency deviation to 4 MHz.
➢ Press the FREQ key and enter 850 MHz.
3. Set the reference level to +10 dBm.
➢ Press the AMPT key and enter 10 dBm.
2.34 Operating Manual 1313.9681.12 - 01