Rohde & Schwarz 1145.1010.04/05/06, Operating Manual

Page: 340 / 813

Channel Menu R&S
®
ZVA/ZVB/ZVT
1145.1084.12 4.178 E-6
•
Fixed Frequency defines the frequency to be assigned to the signal with Fixed frequency
definition.
•
Conversion selects the frequency of the signal with Auto frequency definition, see background
information below.
Conversion formulas
The IF signal can be at the sum or at the difference of the RF and LO frequencies.
•
IF = RF – LO means that the RF signal is down-converted (upper sideband). The analyzer
automatically switches to IF = LO – RF if the LO frequency is above the RF input frequency.
•
IF = LO – RF means that the LO signal is down-converted (lower sideband). The analyzer
automatically switches to IF = RF – LO if the RF input frequency is above the LO frequency.
•
IF = LO + RF means that the RF input signal is up-converted.
In a frequency sweep mode where one of the input frequencies varies over a definite range, the IF
signal also covers a frequency range of the same width. An error message is displayed if the IF
frequency exceeds the maximum frequency range of the analyzer.
If the RF or LO signal is in Auto mode, the formulas for IF are automatically converted, and the analyzer
calculates the RF or LO frequency from the other frequencies.
Remote
control:
[SENSe<Ch>:]FREQuency:CONVersion MIXer:FFIXed <frequency>
[SENSe<Ch>:]FREQuency:CONVersion MIXer:FIXed RF | IF | LO
[SENSe<Ch>:]FREQuency:CONVersion MIXer:FUNDamental RF | IF | LO
[SENSe<Ch>:]FREQuency:CONVersion MIXer:TFRequency DCLower |
DCUPper | UCONversion
[SENSe<Ch>:]FREQuency:STARt
etc.
Mixer Power Cal...
Opens a dialog to perform a power calibration of the signal sources and of the IF receiver. A power
calibration ensures accurate levels of the mixer input signals (RF and LO source power calibration) and
an accurate power measurement of the mixer output signal (IF receiver calibration). The necessary
calibration steps are automatically performed across the entire frequency range of the active mixer
measurement
(Set Frequencies).
Mixer Power Cal procedure and example
Due to the different frequency ranges of the input and output signals and the external equipment
needed, the mixer power calibration must be performed in several steps. For a test setup where the RF
and LO signals are provided by port 1 and an external generator, respectively, where the RF signal is
swept, and where the IF signal is analyzed at port 2, the following test setups are required:
3. Source power calibration for the RF signal. A power sensor is connected to port 1. The RF power (red)
is calibrated over the selected RF sweep range. As a preparative for step 2 the analyzer also calibrates
the source at the fixed IF frequency. The correction data for both calibration sweeps is stored.