R&S ZVB - Page 305

R&S
®
ZVA / R&S
®
ZVB / R&S
®
ZVT GUI Reference
Channel Menu
Operating Manual 1145.1084.12 – 30 290
Frequencies. This option is available for ZVA and ZVT network analyzers only.
 RF Off switches the RF signal source at the port off (box checked) or on for measurements in the
related channel. Dependencies: The column is disabled (grayed) while the RF power is switched
off globally for the active channel. The settings are restored as soon as the RF power is switched
on again. RF Off and Meas are independent from each other: While the RF power is switched off,
the port is not necessarily excluded from the measurement, it can still be used as a receive port.
On the other hand, an excluded port (Meas = Off) can still be used as an RF signal source. The
exact behavior of RF Off is part of the system configuration; refer to the description of the Power
tab.
The RF sources must be switched on to perform a system error correction or a power calibration. In
both cases, the analyzer checks whether any of the required source ports is switched off and
displays a warning, if required.
 Gen qualifies whether the RF signal source at the port is switched on for all partial measurements
(box checked, permanent signal source) or only for the partial measurements that require the port
as a drive port. Dependencies: Gen has no effect unless the RF source at the port is switched on
(RF Off is not checked). A port which is excluded from the measurement (Meas = Off) can still be
used as a permanent RF signal source. If Gen is on, for most analyzers the source frequencies at
port 1 and 2 and at port 3 and 4 are coupled; see note on coupled test ports below. Gen is
unavailable in true differential mode.
External generators
An external generator always represents a permanent signal source that is switched on for all partial
measurements. Gen qualifies whether or not the generator is actually available as a signal source in the
test setup.
The analyzer provides two alternative ways of selecting a generator as a signal source:
 Gen: On in the Port Configuration dialog, especially if the generator is not assigned to a particular
measured quantity or drive port.
 Selection as a source for a particular measured quantity or for a power calibration, see e.g. More
Wave Quantities.
The two selection mechanisms are independent from each other.
Permanent vs. intermittent RF signal source
Switching on the signal source permanently eliminates the power settling times of the DUT but may
introduce measurement inaccuracies, e.g. due to crosstalk between two ports. Therefore, the parameter
must be switched off to perform a system error correction.
 Frequency opens an input box to define a port-specific stimulus frequency range (for frequency
sweeps) or CW frequency (for power, time and CW Mode sweeps). In the default configuration the
stimulus parameters (sweep range, CW Frequency) are used. The result is displayed in the
Frequency Result column. A red Frequency field indicates that the hardware limits are exceeded,
e.g. if the default sweep range of the analyzer is beyond the frequency range of the external