Rohde & Schwarz 1145.1010.04/05/06, Operating Manual

Page: 353 / 813

R&S
®
ZVA/ZVB/ZVT Channel Menu
1145.1084.12 4.191 E-6
Triggered Meas.
Sequence
Alternate On Alternate Off
Sweep Trigger event starts n partial sweeps over all
sweep points.
Trigger event starts m complete measurements at
consecutive sweep points.
Sweep Segment Trigger event starts n partial sweeps over the
next segment.
Trigger event starts complete measurements at all
consecutive sweep points in the segment.
Point All partial measurements of each sweep point
are carried out one after another.
All partial measurements of each sweep point are
carried out one after another.
Partial
Measurement
Each partial measurement is carried out for all
sweep points.
All partial measurements of each sweep point are
carried out one after another
Spurious Avoidance
The Spurious Avoidance submenu defines whether the analyzer measures with a local oscillator
frequency LO below or above the RF input frequency.
This feature can be used to eliminate known spurious components in the input signal that can distort the
measurement, especially in the low frequency range.
•
In Auto mode, the analyzer auto-selects the local oscillator frequency, depending on the
receiver (RF) frequency and the test port. This mode systematically avoids known spurious
signals provided that no frequency conversion occurs in the test setup.
•
LO > RF means that the LO frequency is always above the measured RF frequency. This mode
is appropriate for avoiding single, known spurious signals.
•
LO > RF means that the LO frequency is always below the measured RF frequency. This mode
is appropriate for avoiding single, known spurious signals.
In the presence of several spurious signals, setting the Spurious Avoidance parameter globally
may not be sufficient. To improve the result, perform a Segmented Frequency sweep and assign
independent LO frequencies to the individual sweep segments.
Application example
Consider the following test setup with strongly reflecting DUT (e.g. a bandpass in its stop band) that is
measured in transmission. a
1
is generated at a frequency RF.The reflected wave b
1
falls into the