Concepts and features
R&S
®
ZNA
131
User Manual 1178.6462.02 ─ 20
The four 2-port Y-parameters can be interpreted as follows:
●
Y
11
is the input admittance, defined as the ratio of the current I
1
to the voltage V
1
,
measured at port 1 (forward measurement with output terminated in a short circuit,
V
2
= 0).
●
Y
21
is the forward transfer admittance, defined as the ratio of the current I
2
to the
voltage V
1
(forward measurement with output terminated in a short circuit, V
2
= 0).
●
Y
12
is the reverse transfer admittance, defined as the ratio of the current I
1
to the
voltage V
2
(reverse measurement with input terminated in a short circuit, V
1
= 0).
●
Y
22
is the output admittance, defined as the ratio of the current I
2
to the voltage V
2
,
measured at port 2 (reverse measurement with input terminated in a short circuit,
V
1
= 0).
Y-parameters can be easily extended to describe circuits with more than two ports or
several modes of propagation.
4.3.5
Wave quantities and ratios
The elements of the S-, Z- and Y-matrices represent fixed ratios of complex wave
amplitudes. As long as the assumption of linearity holds, the S-, Z- and Y-parameters
are independent of the source power.
The network analyzer provides two additional sets of measurement parameters which
have an unambiguous meaning even if the DUT is measured outside its linear range:
●
Wave quantities
provide the power of any of the transmitted or received waves.
●
Ratios
provide the complex ratio of any combination of transmitted or received
wave quantities.
In contrast to S-, Z- and Y-parameters, wave quantities and ratios are not system-error
corrected.
To increase the accuracy or to correct a possible attenuation in the source signal path,
it is recommended to perform a power calibration (see
4.3.5.1
Wave quantities
A wave quantity measurement provides the power of any of the transmitted or received
waves. The power can be displayed in voltage units (e.g. V or dBmV) or equivalent
power units (e.g. W or dBm).
Measurement results
