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 RF Blockset Equivalent Baseband Algorithms for
Y-parameters for a two-port passive network in a 2-by-2-by-M array. M is the number of Y-parameters.
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.
The method used to interpolate the network parameters. The following table lists the available methods describes each one.
|Cubic spline interpolation|
|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
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
Set the Frequency (Hz) parameter
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,
Set the Frequency data (Hz) parameter
In the Plot type list, select
Click Plot. This action creates a polar plane plot of the S11 parameters in the frequency range 1.9 to 2.2 GHz.