# design

Design symmetric coupled strip transmission line around given frequency

## Syntax

``csline = design(cslineobj,frequency)``
``csline = design(___,Name,Value)``

## Description

````csline = design(cslineobj,frequency)` designs an coupled strip transmission line around the specified frequency with default even and odd impedances of `55.2` ohms and `45.09` ohms respectively using a λ-by-4 line length.```

example

````csline = design(___,Name,Value)` designs a coupled strip transmission line with additional options specified by name-value pair arguments. NotePCB components designed using the `design` function resonates around the specified frequency with a 10 to 15% tolerance. ```

## Examples

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Design a coupled strip transmission line at 3 GHz for an even and odd mode impedance of 70 ohms and 35 ohms respectively and visualize it.

``` csline = design(coupledStripLine,3e9,'Z0e',70,'Z0o',35); figure; show(csline);```

Plot the s-parameters of the transmission line at 3 GHz.

```spar = sparameters(csline,3e9); rfplot(spar)```

## Input Arguments

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Coupled strip transmission line, specified as a `coupledStripLine` object.

Example: `csline = coupledStripLine; design(csline,2e9)` designs a coupled strip transmission line around a frequency of 2 GHz.

Resonant frequency of the transmission line, specified as a real positive scalar.

Example: `55e6`

Data Types: `double`

### Name-Value Arguments

Specify optional comma-separated pairs of `Name,Value` arguments. `Name` is the argument name and `Value` is the corresponding value. `Name` must appear inside quotes. You can specify several name and value pair arguments in any order as `Name1,Value1,...,NameN,ValueN`.

Example: `'Z0e',53`

Even mode impedance of the transmission line in ohms, specified as the comma-separated pair consisting of `'Z0e'` and a positive scalar.

Data Types: `double`

Odd mode impedance of the transmission line in ohms, specified as the comma-separated pair consisting of `'Z0e'` and a positive scalar.

Data Types: `double`

## Output Arguments

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Coupled strip transmission line operating around the specified reference frequency, returned as a `coupledStripLine` object.