Model passive network using Y-parameters

Black Box Elements sublibrary of the Physical library

The Y-Parameters Passive Network block models the two-port passive network described in the block dialog box, in terms of its Y-parameters and their associated frequencies.

In the **Y-Parameters** field of the block
dialog box, provide the Y-parameters for each of M frequencies as
a 2-by-2-by-M array. In the **Frequency** field,
specify the frequencies for the Y-parameters as an M-element vector.
The elements of the vector must be in the same order as the Y-parameters.
All frequencies must be positive. For example, the following figure
shows the correspondence between the Y-parameters array and the vector
of frequencies.

The Y-Parameters Passive Network block uses the RF Toolbox™ `y2s`

function to convert the Y-parameters to
S-parameters, and then interpolates the resulting S-parameters to
determine their values at the modeling frequencies. The modeling frequencies
are determined by the Output Port block. See SimRF Equivalent Baseband Algorithms for
more details.

**Y-Parameters**Y-parameters for a two-port passive network in a 2-by-2-by-M array. M is the number of Y-parameters.

**Frequency (Hz)**Frequencies of the Y-parameters as an M-element vector. The order of the frequencies must correspond to the order of the Y-parameters in

**Y-Parameters**. All frequencies must be positive.**Interpolation method**The method used to interpolate the network parameters. The following table lists the available methods describes each one.

Method Description `Linear`

(default)Linear interpolation `Spline`

Cubic spline interpolation `Cubic`

Piecewise cubic Hermite interpolation

For information about plotting, see Create Plots.

The following example specifies Y-parameters [.23i, -.12i; -.12i,
.23i] and [.02-.13i, -.02+.25i; -.02+.25i, .02-.13i] at frequencies
2.0 GHz and 2.1 GHz respectively. It uses the MATLAB^{®} `cat`

function to create the 2-by-2-by-2
Y-parameters array.

cat(3,[.23i,-.12i;-.12i,.23i],... [.02-.13i,-.02+.25i;-.02+.25i, .02-.13i])

Type the following command at the MATLAB prompt to create a variable called

`yparams`

that stores the values of the Y-parameters.yparams = cat(3,[.23i,-.12i;-.12i,.23i],... [.02-.13i,-.02+.25i;-.02+.25i, .02-.13i])

Set the Y-Parameters Passive Network block parameters on the

**Main**tab as follows:Set the

**Y-Parameters**parameter to`yparams`

.Set the

**Frequency (Hz)**parameter to`[2.0e9,2.1e9]`

.

Click

**Apply**. This action applies the specified settings.Set the Y-Parameters Passive Network block parameters on the

**Visualization**tab as follows:In the

**Source of frequency data**list, select`User-specified`

.Set the

**Frequency data (Hz)**parameter to`[1.9e9:1.0e8:2.2e9]`

.In the

**Plot type**list, select`Polar plane`

.

Click

**Plot**. This action creates a polar plane plot of the S_{11}parameters in the frequency range 1.9 to 2.2 GHz.

General Circuit Element, General Passive Network, Output Port, S-Parameters Passive Network, Z-Parameters Passive Network

`y2s`

(RF Toolbox)

`interp1`

(MATLAB)

Was this topic helpful?