R&S ZNA26 - Page 284

Concepts and features
R&S
®
ZNA
284User Manual 1178.6462.02 ─ 20
step attenuator, which can be freely set and therefore allowing to optimize the input
compression and noise behavior at this measurement receiver. See Figure 4-42.
●
The R&S ZNA must be equipped with a receiver step attenuator at port 1 (option
R&S ZNAxx-B31)
●
Currently, internal low power spur reduction amplifiers are not available for
R&S ZNA50 and R&S ZNA67
Ref. receiver
Meas. receiver
B501
R&S®ZNAxx-B501:
Low Power Spur Reduction
30 dB
Ref Out
Ref In
Meas Out
Meas In
Source Out
Source In
10 dB
Source
Port 1
REF SOURCE MEAS
OUT
IN
OUT
IN
Src Mon
Out
Port 1
Figure 4-42: Internal Low Power Spur Reduction Amplifier circuitry: standard
To suppress the overall LO leakage at the port further, it is recommended to use the
Direct source monitor access at port 1 (option R&S ZNAxx-B161). This configuration
suppresses the LO leakage of the reference receiver. A full schematic showing the
internal configuration is shown in Figure 4-43.
Port 1
Ref Out
Ref In
Meas Out
Meas In
Source Out
Source In
-20 dB
Ref. receiver
Meas. receiver
10 dB
Source
R&S®ZNAxx-B501:
Low Power Spur Reduction
30 dB
R&S®ZNAxx-B161:
Direct Source Monitor Access
Src Mon Out
R&S®ZNAxx-B31:
Receiver step att
(0-35 dB/5 dB)
R&S®ZNAxx-B21:
Source step att
(0-70 dB/10 dB)
REF SOURCE MEAS
OUT
IN
OUT
IN
Src Mon
Out
Port 1
Figure 4-43: Internal Low Power Spur Reduction Amplifier with Direct Source Monitor Access
A simplified schematic showing only the relevant components for operation with only
minor LO leakage is shown in Figure 4-44.
Optional extensions and accessories