Concepts and features
R&S
®
ZNA
283User Manual 1178.6462.02 ─ 29
4.7.7.1 Leveling
Introduction
The "Leveling" functionality of the vector network analyzer can be used to linearize the
output power of a connected mm-wave converter over a wide range of power levels
and frequencies. Based on an existing reference receiver calibration, it records the
converter's power transfer function and creates a data set which compensates for the
converter's nonlinearities. Leveling enables converter output power sweeps of up to 70
dB and thus is particularly beneficial for intercept or compression point measurements.
●
Before firmware version 2.40, the leveling functionality was provided by the sepa-
rate R&S Converter Leveling Tool. This tool is no longer required and can no lon-
ger be used with the R&S ZNA.
●
Best leveling results are obtained for frequency converters R&S ZCxxx, R&S ZVA-
Z110 Var.03, and R&S ZVA-Z90. Other frequency converters have limited ability to
control the RF output power via the RF input power and therefore generally do not
allow for effective power correction over wide frequency and power ranges.
●
Controlling the electronic attenuator of an E-type converter is not supported by the
R&S ZNA. However, E-type converters can also be used with their default (unatte-
nuated) output power.
Without leveling data (default or recorded), the measurement is performed at fixed RF
source and LO power. No power sweep is possible. To reduce the actual output power
of the converters (e.g. for measuring wave quantities or testing compression effects),
turn the adjusting knob on top of the converters clockwise. You will see an effect on the
output power within the last 2 mm of the adjustable range.
Although the leveling functionality is enabled with option R&S ZNA-K8 and is designed
for converter ports, it can also be used for regular VNA ports.
Leveling procedure
The purpose of frequency converter leveling is to determine the nominal RF input
power P
RF-In
at the converter input that is required to generate a particular RF converter
output power P
RF-Out
at (output) frequency f.
To this end, the RF output power is measured on a "leveling grid", i.e. at equidistant RF
input power levels P
RF-In, i
and frequencies f
j
. Two-dimensional interpolation is then
used to obtain the appropriate input level for the desired output level at a given fre-
quency. Selecting smaller step sizes can improve the interpolation accuracy, at the cost
of an increased leveling duration.
Frequency converter leveling can be performed via the standard Power Cal wizard. For
each frequency converter port, the leveling procedure consists of the following steps:
1. Source flatness calibration (optional)
Optional extensions and accessories
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