R&S ESR Series User Manual page 452

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R&S ESR
width can be obtained using correction factors. These correction factors are normally
used by the signal analyzer's internal power measurement routines in order to deter-
mine the signal power from IF envelope measurements. These factors apply if and only
if the assumption of a Gaussian amplitude distribution is correct.
Apart from this common method, the R&S ESR also has a true power detector, i.e. an
RMS detector. It correctly displays the power of the test signal within the selected reso-
lution bandwidth irrespective of the amplitude distribution, without additional correction
factors being required. The absolute measurement uncertainty of the FSV is < 1.5 dB
and a relative measurement uncertainty of < 0.5 dB (each with a confidence level of
95 %).
There are two possible methods for measuring channel and adjacent channel power
with a signal analyzer:
1. IBW method (Integration Bandwidth Method)
The signal analyzer 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
Intrinsic Noise of the R&S ESR at 1 GHz in a 1.23 MHz Channel Bandwidth with
the Channel Power Function"
2. Using a channel filter
For a detailed description, refer to the following section.
Measurements using a channel filter
In this case, the signal analyzer makes zero span measurements 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 opti-
mized for a particular transmission method.
The R&S ESR has test routines for simple channel and adjacent channel power mea-
surements. These routines give quick results without any complex or tedious setting
procedures.
Measurement Example 1 – ACPR Measurement on an CDMA2000 Signal
Test setup:
User Manual 1175.7068.02 ─ 12
Advanced Measurement Examples
"Measurement Example – Measuring the
on page 445.
Spectrum Measurements
449