Common Measurement Settings
R&S
®
FSW
360
User Manual 1173.9411.02 ─ 19
Two-port mixer
Three-port mixer
In both cases, the nominal LO level is 15.5
dBm.
Bias Current
Single-diode mixers generally require a DC voltage which is applied via the LO line.
This DC voltage is to be tuned to the minimum conversion loss versus frequency. Such
a DC voltage can be set via the "BIAS" function using the D/A converter of the
R&S
FSW. The value to be entered is not the voltage but the short-circuit current. The
current is defined in the "Bias Settings" or set to the value of the conversion loss table
(see
on page 371 and
Fig. 6-14: Bias circuit of the R&S
FSW
The voltage U
0
at the output of the operational amplifier can be set in the range –2.0 to
+2.0 V. An open-circuit voltage V
bias
of –0.5 to +0.5 V is obtained accordingly at the
output of the voltage divider. A short-circuit current of I
short
= V
0
/ 200
Ω
= 10 mA to +
10 mA is obtained for a short circuit at the output of the voltage divider. In order to use
Data Input and Output
