R&S 1311.6010K22, Руководство пользователя

Страница: 127 / 1611

Concepts and features
R&S
®
ZNB/ZNBT
127 User Manual 1173.9163.02 ─ 62
Table 4-3: Squared S-parameters
|a
i
| 2
Available incident power (= the power provided by a generator with
a source impedance equal to the reference impedance Z
0
) at DUT
port i=1,2
|b
i
|
2 Reflected power at DUT port i=1,2
10 log|S
ii
|
2
= 20 log|S
ii
|
Reflection loss at DUT port i=1,2
10 log|S
21
| 2 = 20 log|S
21
|
Insertion loss of forward transmission
10 log|S
12
| 2 = 20 log|S
12
|
Insertion loss of reverse transmission
4.3.1.1 Multiport S-parameters
The multiport S-parameters extend the standard 2-port S-parameters to a larger num-
ber of incident and outgoing waves. For a 4-port DUT,












































a
a
a
a
S S S S
S S S S
S S S S
S S S S
b
b
b
b
4
3
2
1
44 43 42 41
34 33 32 31
24 23 22 21
14 13 12 11
4
3
2
1
where again a
i
(i = 1 to 4) denote the incident, b
i
(i = 1 to 4) denote the outgoing waves,
and the S-parameters are expressed as S
ij
(i,j = 1 to 4).
The indices of the S-parameters described so far number the output and input ports of
a DUT; the parameters are referred to as single-ended S-parameters. The S-parameter
description can also be used to differentiate between different propagation modes of
the waves at the output and input ports. This results in the so-called mixed mode S-
parameters. The analyzer measures either single-ended or mixed mode S-parameters.
4.3.1.2 Redefined S-parameters
The analyzer firmware allows you to redefine the physical VNA ports, simply by speci-
fying:
●
a reference receiver ("a wave")
●
a measurement receiver ("b wave")
●
a generator ("Source" VNA or external generator port)
As a consequence, the measured S-parameters and other measured quantities are
also redefined.
●
The receivers and generators can be freely assigned, but without reusing the same
(original) physical port in different (redefined) ports. See
Chapter 5.18.5.2, "Define
Physical Ports dialog" , on page 791.
●
Redefined physical ports are global, persistent settings, i.e. they are valid for all
recall sets. A [Preset] does not reset the physical port configuration.
●
Redefining physical ports causes a factory reset.
The factory reset deletes all switch matrix RF connections.
Measurement results