R&S 1332.4500K22, Руководство пользователя

Страница: 282 / 1709

Concepts and features
R&S
®
ZNA
282 User Manual 1178.6462.02 ─ 20
●
For R&S ZNA50 and R&S ZNA67, this option is not yet available.
●
For 2-port R&S ZNA, an internal combiner is not yet available.
●
Option R&S ZNAxx-B2 13 requires source step attenuators at physical ports 1 and
3 , i.e. HW options R&S ZNAxx-B2 1 and R&S ZNAxx-B2 3
See Chapter 4.7.28, "Source step attenuators" , on page 278.
●
To retrofit the internal combiner, the R&S ZNA must be sent to Rohde & Schwarz
service.
4.7.35 Internal low noise preamplifier
Hardware option R&S ZNA26-B302 | R&S ZNA43-B302
Hardware option R&S ZNAxx-B302 provides an internal low noise pre-amplifier (LNA)
at receive port 2 of a R&S ZNAxx.
The LNA can apply a power gain of 20 dB, 25 dB, or 30 dB. and is installed in parallel
to the receiver step attenuator .
●
The R&S ZNA must be equipped with a receiver step attenuator at port 2 (option
R&S ZNAxx-B32)
●
Currently, internal LNAs are not available for R&S ZNA50 and R&S ZNA67
The internal LNA reduces the noise figure of the receiver at port 2 of the R&S ZNA,
improving the quality of its Chapter 4.7.11, "Noise figure measurement" , on page 260.
A schematic of the internal circuitry is shown in Figure 4-39 .
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:
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 n
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 .
Optional extensions and accessories