eldo_user

Working with S, Y, Z Parameters
S, Y, Z Parameter Extraction
• LPORT
Inductor placed in series (for V source) or parallel (for I source) with RPORT. Defaults to 0.
• ZPORT_FILE=filename
Specifies the Touchstone file containing the complex port impedances from which the
S parameters are extracted.
The port impedance file should be 1-port. The Z-parameters represent a passive load and
does not contain the source. For example:
# Hz Z RI R 50
!Freq.[Hz] R[ohm] I[ohm]
1800000000 50 0
1801000000 50 0
3600000000 50 0
3602000000 50 0
5400000000 50 0
5403000000 50 0
6000000000 50 0
• MODE=SINGLE|COMMON|DIFFERENTIAL
Mixed-mode S parameter selection.
SINGLE specifies the port as single ended, it is dedicated to S parameter extraction.
Default.
COMMON and DIFFERENTIAL specify that the port is not single ended. Such ports are
split into two linked sources that are either common (same amplitude and same phase) or
differential (same amplitude but opposite phases). During S parameter extraction a “nonsingle
ended” port is equally common and differential depending on which display is
required. During simulation (DC, AC or TRAN) this port is either common or differential
depending on the specified mode keyword.
Note
Port numbers in Vyy instances should range from 1 to the total number of ports without
discontinuity. The simulation parameters FMIN, FMAX, and Number of frequency points
for the analysis are specified with a .AC command.
S, Y, Z Parameter Extraction
Once the simulation has been setup, S, Y, Z parameters can be extracted during simulation by
use of the .PRINT and .PLOT commands as described in the following subsections.
Tip
See “Simulation Setup for S, Y, Z Parameter Extraction” on page 684.
Eldo® User's Manual, 15.3 685