Rohde & Schwarz R&S ZNA Series - Page 313

Concepts and features
R&S
®
ZNA
313User Manual 1178.6462.02 ─ 29
Ref Out
Ref In
Meas Out
Meas In
Source Out
Source In
Ref. receiver
Meas. receiver
10 dB
Source
Port 2
R&S®ZNAxx-B32:
Receiver step att
(0-35 dB/5 dB)
R&S®ZNAxx-B302/312:
Low noise amplifier
(20-30 dB / 5 dB)
R&S®ZNAxx-B22:
Source step att
(0-70 dB/10 dB)
REF SOURCE MEAS
OUT
IN
OUT
IN
Port 2
Figure 4-39: LNA circuitry: standard
For optimum receiver noise performance, it is recommended to use the Direct genera-
tor/receiver access in the reversed coupler configuration, as shown in Figure 4-40.
Ref. receiver
Meas. receiver
10 dB
Port 2
Source
R&S®ZNAxx-B32:
R&S®ZNAxx-B22:
Ref Out
Ref In
Meas Out
Meas In
Source Out
Source In
Source step att
(0-70 dB/10 dB)
Receiver step att
(0-35 dB/5 dB)
R&S®ZNAxx-B302/312:
Low noise amplifier
(20-30 dB / 5 dB)
REF SOURCE MEAS
OUT
IN
OUT
IN
Port 2
Figure 4-40: LNA circuitry: direct access with reversed coupler configuration
This configuration changes the connection of the source and the receiver at the cou-
pler, as can be clearly seen in the simplified schematic in Figure 4-41. The LNA and
the cascaded receiver are therefore directly connected to the port without coupling
loss, which further improves the overall receiver noise figure.
Optional extensions and accessories