Passive component or network
Use the rlcgline
object to represent RLCG transmission
lines that are characterized by line loss, line length, stub type, and
termination.
h = rfckt.rlcgline
returns an RLCG transmission line
object whose properties are set to their default values.
h = rfckt.rlcgline('Property1',value1,'Property2',value2,...)
sets properties using one or more name-value pairs. You can specify multiple
name-value pairs. Enclose each property name in a quote
analyze | Analyze RFCKT object in frequency domain |
calculate | Calculate specified parameters for rfckt objects or rfdata objects |
circle | Draw circles on Smith Chart |
extract | Extract specified network parameters from rfckt object or data object |
listformat | List valid formats for specified circuit object parameter |
listparam | List valid parameters for specified circuit object |
loglog | Plot specified circuit object parameters using log-log scale |
plot | Plot specified circuit object parameters on X-Y plane |
plotyy | Plot specified parameters on X-Y plane with Y-axes on both left and right sides |
getop | Display operating conditions |
polar | Plot specified object parameters on polar coordinates |
semilogx | Plot specified circuit object parameters using log scale for x-axis |
semilogy | Plot specified circuit object parameters using log scale for y-axis |
smith | Plot specified circuit object parameters on Smith chart |
write | Write RF data from circuit or data object to file |
getz0 | Get characteristic impedance of transmission line object |
read | Read RF data from file to new or existing circuit or data object |
restore | Restore data to original frequencies |
getop | Display operating conditions |
groupdelay | Group delay of S-parameter object or RF filter object or RF Toolbox circuit object |
The analyze
method treats the transmission line, which can be lossy
or lossless, as a 2-port linear network. It uses the interpolation method you specify in
the IntpType
property to find the R, L, C, and G values at the
frequencies you specify when you call analyze
. Then, it calculates
the characteristic impedance, Z0, phase velocity, PV, and loss using these interpolated
values. It computes the AnalyzedResult
property of a stub or as a
stubless line using the data stored in the rfckt.rlcgline
object
properties as follows:
If you model the transmission line as a stubless line, the
analyze
method first calculates the ABCD-parameters
at each frequency contained in the modeling frequencies vector. It then uses
the abcd2s
function to convert the
ABCD-parameters to S-parameters.
The analyze
method calculates the ABCD-parameters using
the physical length of the transmission line, d, and the
complex propagation constant, k, using the following equations:
Z0 and k are
vectors whose elements correspond to the elements of f,
the vector of frequencies specified in the analyze
input
argument freq
. Both can be expressed in terms of the
resistance (R), inductance (L),
conductance (G), and capacitance
(C) per unit length (meters) as follows:
If you model the transmission line as a shunt or series stub, the
analyze
method first calculates the ABCD-parameters
at the specified frequencies. It then uses the abcd2s
function to convert the ABCD-parameters to S-parameters.
When you set the StubMode
property to
'Shunt'
, the 2-port network consists of a stub
transmission line that you can terminate with either a short circuit or an
open circuit as shown in the following figure.
Zin is the input impedance of the shunt circuit. The ABCD-parameters for the shunt stub are calculated as:
When you set the StubMode
property to
'Series'
, the 2-port network consists of a series
transmission line that you can terminate with either a short circuit or an
open circuit as shown in the following figure.
Zin is the input impedance of the series circuit. The ABCD-parameters for the series stub are calculated as:
The analyze
method uses the S-parameters to calculate the group
delay values at the frequencies specified in the analyze
input
argument freq
, as described in the analyze
reference page.
[1] Ludwig, R. and P. Bretchko, RF Circuit Design: Theory and Applications, Prentice-Hall, 2000
rfckt.amplifier
| rfckt.cascade
| rfckt.coaxial
| rfckt.cpw
| rfckt.datafile
| rfckt.delay
| rfckt.hybrid
| rfckt.hybridg
| rfckt.microstrip
| rfckt.mixer
| rfckt.parallel
| rfckt.parallelplate
| rfckt.passive
| rfckt.series
| rfckt.seriesrlc
| rfckt.shuntrlc
| rfckt.twowire
| rfckt.txline