Technical data

558 Chapter 19
W-CDMA or W-CDMA (with HSDPA) Analyzer
W-CDMA or W-CDMA (with HSDPA) Analyzer Measurement Settings
W-CDMA or W-CDMA (with HSDPA)
Analyzer
Compensating for the Loss or Gain of External Cables,
Attenuators, and Preamps
The insertion loss of the test cable and high power attenuator must be compensated
for to obtain accurate W-CDMA or W-CDMA (with HSDPA) power measurements,
such as channel power. This process is called normalization and is described in
“Measuring Two Port Insertion Loss” on page 124.
The insertion loss of the test cable/attenuator combination is accounted for as the RF
In Loss, which is an offset applied to the power measurements by the test set.
Similarly, the insertion gain of an external preamp must be compensated for to
obtain accurate W-CDMA or W-CDMA (with HSDPA) measurements.Although an
external preamp produces a gain rather than a loss, this is also compensated for
using RF In Loss. To enter a gain figure for a preamp, you must enter a negative loss
figure. For example, to enter a gain of 20 dB, you must enter “–20 dB” here.