Performing A Channel Power Measurement, Using Immediate Trigger - Keysight Technologies M9393A Programming Manual

The figure below shows a simplified block diagram for the M9381A PXIe VSG and
M9393A PXIe VSA in a typical PA / FEM test system.
Typical power amplifier modules require an input power level of 0 to + 5 dBm,
digitally modulated according to communication standards such as WCDMA or
LTE. The specified performance of the power amplifier or front end module is
normally set at a specific output level of the DUT. If the devices have small
variations in gain, it may be necessary to adjust the power level from the M9381A
PXIe VSG to get the correct output level of the DUT. Only after the DUT output
level is set at the correct value can the specified parameters be tested. The time
spent adjusting the M9381A PXIe VSG to get the correct DUT output power can be
a major contributor to the test time and the overall cost of test.
The M9381A PXIe VSG is connected to the DUT using a cable and switches. The
switching may be used to support testing of multi-band modules or multi-site
testing. The complexity of the switching depends on the number of bands in the
devices and the number of test sites supported by the system. The DUTs are
typically inserted into the test fixture using an automated part handler. In some
cases, several feet of cable is required between the M9381A PXIe VSG and the
input of the DUT.
The combination of the RF cables and the switching network can add several dB of
loss between the output of the M9381A PXIe VSG and the input of the DUT, which
requires higher output levels from the M9381A PXIe VSG. Since the tests are
performed with a modulated signal, the M9381A PXIe VSG must also have
adequate modulation performance at the higher power levels.
Performing a Channel Power Measurement, Using Immediate
Trigger
41
Standard Sample
Rate
WCDMA 5 MHz
LTE 10 MHz 11.25
FDD MHz
Channel Filter Channel Filter
Type Parameter
RRC 0.22
Rectangular N/A
Keysight M9393A PXIe Performance Vector Signal Analyzer
Channel Filter Channel
Bandwidth Offsets
3.84 MHz 5, 10 MHz
9 MHz 10, 20
MHz