# Parallel-Plate Transmission Line

Model parallel-plate transmission line

• Library:
• RF Blockset / Equivalent Baseband / Transmission Lines

• ## Description

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. ## Parameters

expand all

Main

Physical width of the parallel-plate transmission line.

Thickness of the dielectric separating the plates.

Relative permeability of the dielectric expressed as the ratio of the permeability of the dielectric to permeability in free space μ0.

Relative permittivity of the dielectric expressed as the ratio of the permittivity of the dielectric to permittivity in free space ε0.

Loss angle tangent of dielectric, specified as a scalar.

Conductivity is a metric to measure the flow of current in a conductor.

Physical length of the transmission line in meters.

The block enables you to model the transmission line as a stub or as a stubless line.

#### Stubless Transmission 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.

#### Shunt and Series Stubs

• 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

`$\begin{array}{c}A=1\\ B=0\\ C=1/{Z}_{in}\\ D=1\end{array}$`
• `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

`$\begin{array}{c}A=1\\ B={Z}_{in}\\ C=0\\ D=1\end{array}$`

Stub termination for stub modes `Shunt` and `Series`. Choices are `Open` or `Short`

#### Dependencies

To enable this parameter, select `Shunt`, or `Series`, or in Stub mode

Visualization

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 range, specified as a vector

Reference impedance of the parallel-plate transmission line, specified as a scalar in ohms.

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.

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.

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.

Plot format, specified as one of the following ```Magnitude (decibels)```, `Angle(degrees)`, `Real`, or `Imaginary`.

Plot format, specified as one of the following ```Magnitude (decibels)```, `Angle(degrees)`, `Real`, or `Imaginary`.

Parameter, specified as `Freq`.

Plot format, specified as one of the following `Hz`, `Auto`, `KHz`, `MHz`, `GHz` or `THz`.

Y-axis scale, specified as `Linear` or `Logarithmic`.

X-axis scale, specified as `Linear` or `Logarithmic`.

Plot specified data using plot button.