eldo_user

Working with S, Y, Z Parameters
Output File Specification
Examples
r1 1 2 100k
c1 2 0 10pf
V1 1 0 iport=1 rport=100
V2 2 0 iport=2 rport=20
.ac dec 10 1 100meg
.plot ac sdb(2,1)
.Ffile S sb1.par khz ri
In this example, the S parameters of an RC circuit are extracted between 1Hz and 100MHz with
10 points per decade. The reference impedance is 100 for port1 and 20 for port2. The magnitude
of S21 is plotted in dB, and the extracted S parameters are stored in the file sb1.par with the
frequency in kHz. The data is stored in the form of the Real and Imaginary parts.
V1 1 0 iport=1 rport=50
R1 1 n1 1k
C1 n1 0 100p
R2 n1 2 1k
Rc1 n1 0 100k
V2 2 0 iport=2 rport=50
.ac lin 21 1meg 21meg
.noise v(n1) V1 3
.plot noise rneq gopt bopt nfmin_mag
.ffile Z Z.par kHz ma
In this example the Z parameters are being extracted between 1MHz and 21MHz with 21
analysis points. The extracted Z parameters are stored in the file Z.par with the frequency in
kHz. The data is stored in the form of the Magnitude Angle. As the circuit is a two-port circuit
and there is a .NOISE command specified in the netlist then the two-port noise parameters are
also stored in the output file. The output file is shown below:
! Data from test
# KHZ Z DB R 5.000000E+01
!
1.0000000000000000E+03 6.5542511585029786E+01 -5.7202544106307606E+01
6.4035302689753806E+01 -8.9088186330215692E+01 6.4035302689753806E+01
-8.9088186330215706E+01 6.5542511585029786E+01 -5.7202544106307606E+01
...
2.1000000000000000E+04 6.0025369785355387E+01 -4.3338006361865595E+00
3.7592014242230192E+01 -8.9956576643609139E+01 3.7592014242230199E+01
-8.9956576643609139E+01 6.0025369785355402E+01 -4.3338006361865711E+00
! Noise Data: Nfmin(dB) GammaOpt PhiOpt Rneq/R0
1.0000000000000000E+03 5.2661113010469025E+00 9.6890047604421903E-01
1.7851510536508835E+02 4.8497683522933400E+01
...
2.1000000000000000E+04 2.8441528902447214E+01 9.0554147314402922E-01
1.7956971588917614E+02 3.5225984336136335E+03
Eldo® User's Manual, 15.3 689