Model parallel-plate transmission line
RF Blockset / Equivalent Baseband / Transmission Lines
The Parallel-Plate Transmission Line block models the parallel-plate transmission line described in the block dialog box in terms of its frequency-dependent S-parameters. A parallel-plate transmission line is shown in cross-section in the following figure. Its physical characteristics include the plate width w and the plate separation d.
Plate width (m)
— Width of parallel-plate transmission line5e-3
(default) | scalarPhysical width of the parallel-plate transmission line.
Plate separation (m)
— Dielectric spacing in parallel-plate transmission line1e-3
(default) | scalar Thickness of the dielectric separating the plates.
Relative permeability constant
— Relative permeability of the dielectric material in the parallel-plate transmission line1
(default)Relative permeability of the dielectric expressed as the ratio of the permeability of the dielectric to permeability in free space μ0.
Relative permittivity constant
— Relative permittivity of the dielectric material in the parallel-plate transmission line2.3
(default)Relative permittivity of the dielectric expressed as the ratio of the permittivity of the dielectric to permittivity in free space ε0.
Loss tangent of dielectric
— Loss tangent of dielectric in the parallel-plate transmission line0
(default)Loss angle tangent of dielectric, specified as a scalar.
Conductivity of the conductor (S/m)
— Conductivity of the conductor in siemens per meterinf
(default)Conductivity is a metric to measure the flow of current in a conductor.
Transmission line length(m)
— Physical length of the transmission line0.01
(default)Physical length of the transmission line in meters.
Stub mode
— Type of stubNot a stub
(default) | Shunt
| Series
The block enables you to model the transmission line as a stub or as a stubless line.
Not a stub
—Not a
stub
If you model a parallel-plate transmission line as stubless
line, the Parallel-Plate Transmission Line block 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. For more
information, see Stub Mode- Not a stub.
The stub mode of the parallel-plate transmission line is classified as following:
Shunt
—Shunt
parameter provides the users with the two-port network consists
of a stub transmission line that you can terminate with either a
short circuit or an open circuit as shown here.
Zin is the input impedance of the shunt circuit. The ABCD-parameters for the shunt stub are calculated as
Series
—Series
parameter provides the user with the two-port network consists
of a series transmission line that you can terminate with either
a short circuit or an open circuit as shown here.
Zin is the input impedance of the series circuit. The ABCD-parameters for the series stub are calculated as
Termination of stub
— Stub termination Open
(default)Stub termination for stub modes Shunt
and
Series
. Choices are Open
or
Short
To enable this parameter, select Shunt
, or
Series
, or in Stub
mode
Source of frequency data
— Frequency data sourceUser-defined
(default)When Source of frequency data is
User-specified
, specify a vector of
frequencies in the Frequency data parameter. Also,
specify units from the corresponding drop-down list.
Frequency data
— Frequency data range[1e9:1e6:3e9]
(default) | vector | Hz
| kHz
| MHz
| GHz
Frequency data range, specified as a vector
Reference impedance(ohms)
— Reference impedance50
(default) | scalar Reference impedance of the parallel-plate transmission line, specified as a scalar in ohms.
Plot type
— Type of data plotX-Y plane
(default) | Polar plane
| Z Smith chart
| Y Smith chart
| ZY Smith chart
Type of data plot that you want to produce with your data specified as one of the following:
X-Y plane
— Generate a Cartesian
plot of your data versus frequency. To create linear, semi-log, or
log-log plots, set the Y scale and X
scale accordingly.
Polar plane
— Generate a polar
plot of your data. The block plots only the range of data
corresponding to the specified frequencies.
Z smith chart
, Y smith
chart
, and ZY smith
chart
— Generate a Smith® chart. The block plots only
the range of data corresponding to the specified frequencies.
Y Parameter 1
— Type of S-Parameters to plotS21
(default) | S11
| S12
| S22
| GroupDelay
| GammaIn
| GammaOut
| VSWRIn
| VSWROut
| OIP3
| IIP3
| NF
| NFactor
| NTemp
| TF1
Type of S-Parameters to plot, specified as one of the following
S11
, S12
, S21
,
or S22
. When noise is spectral NF
,
NFactor
, NTemp
plotting is
possible.
Y Parameter 2
— Type of S-Parameters to plotS11
(default) | S12
| S21
| S22
| GroupDelay
| GammaIn
| GammaOut
| VSWRIn
| VSWROut
| OIP3
| IIP3
| NF
| NFactor
| NTemp
| TF1
Type of S-Parameters to plot, specified as one of the following
S11
, S12
, S21
,
or S22
. When noise is spectral NF
,
NFactor
, NTemp
plotting is
possible.
Y Format1
— Plot formatAngle(degrees)
(default) | Magnitude (decibels)
| Real
| Imaginary
Plot format, specified as one of the following Magnitude
(decibels)
, Angle(degrees)
,
Real
, or Imaginary
.
Y Format2
— Plot formatMagnitude (decibels)
(default) | Angle(degrees)
| Real
| Imaginary
Plot format, specified as one of the following Magnitude
(decibels)
, Angle(degrees)
,
Real
, or Imaginary
.
X parameter
— X parameterFreq
(default)Parameter, specified as Freq
.
X format
— Plot formatHz
(default) | Auto
| KHz
| MHz
| GHz
| THz
Plot format, specified as one of the following Hz
,
Auto
, KHz
, MHz
,
GHz
or THz
.
Y scale
— Y-axis scaleLinear
(default) | Logarithmic
Y-axis scale, specified as Linear
or
Logarithmic
.
X scale
— X-axis scaleLinear
(default) | Logarithmic
X-axis scale, specified as Linear
or
Logarithmic
.
Plot
— Plot specified dataPlot specified data using plot button.
The block 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, a vector of modeling frequencies, determined by the Output Port block. Both can be expressed in terms of the resistance (R), inductance (L), conductance (G), and capacitance (C) per unit length (meters) as follows:
where
In these equations:
a is the radius of the inner conductor.
b is the radius of the outer conductor.
σcond is the conductivity in the conductor.
μ is the permeability of the dielectric. μ = μ0 μr where:
μ0 is the permeability in free space.
μr is the Relative permeability constant parameter value.
The is a complex dielectric constant given by ε = ε′ − јε″= ε′ ( 1 − јtanδ)
ε′ is the real part of complex dielectric constant ε, ε′ = ε0εr. ε″ is the imaginary part of complex dielectric constant ε, ε″ = ε0εrtan δ where :
ε0 is the permittivity of free space.
εr is the Relative permittivity constant parameter value.
tan δ is the Loss tangent of dielectric parameter value.
δcond is the skin depth of the conductor, which the block calculates as .
[1] Pozar, David M “Microwave Engineering”, John Wiley & Sons, Inc., 2005.
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