SParameterChannel
R2026bConvert S-parameter to impulse response
Description
The SParameterChannel object combines the scattering parameter
(S-parameter) model of a baseband communication channel with an analog transmitter and
receiver into a single S-parameter with adjustable port ordering. The object then calculates
the impulse response of the S-Parameter using the rational (RF Toolbox) function.
The SParameterChannel object supports .sNp Touchstone files, where N represents the number of ports.
Creation
Description
creates an S-parameter channel object obj = SParameterChannel(filename)obj by importing data from the
Touchstone file specified by filename.
Input Arguments
Touchstone data file that contains network parameter data, specified as a character
vector or string scalar. filename can be the name of a file on
the MATLAB® path or the full path to a file.
The data file can be formatted either as a Touchstone 1.1 or Touchstone 2.0 file. (since R2023b)
Properties
The name of the Touchstone data file from where you want to import the S-parameter data, specified as a character vector or string scalar.
Data Types: char | string
Define how the incoming signal is transmitted through wires:
differential— Transmit the incoming signal using a differential pair of signals. The receiver responds to the difference between the two signals.single-ended— Transmit the incoming signal using a varying voltage. The receiver responds to the difference between the incoming signal and a reference or ground.
Port order for the S-parameter, specified as a character vector. If left blank, the function automatically detects the through paths and the re-orders the ports in the order [in1 out1 in2 out2].
Example: [1 2 3 4]
Data Types: char
Maximum number of poles to use to fit a rational model, specified as a positive scalar integer.
Data Types: double
Desired error tolerance for rational model fit, specified as a real scalar in dB.
Data Types: double
Sample interval of the impulse response, specified as a positive real scalar in seconds.
Data Types: double
Desired duration of the impulse response, specified as a positive real scalar in
seconds. The total number of samples in the impulse response is calculated by dividing
the StopTime property by SampleInterval
property.
Data Types: double
Single-ended resistance of the transmitter analog model on the left side of the S-parameter, specified as a nonnegative real scalar in ohms.
Data Types: double
Capacitance of the transmitter analog model on the left side of the S-parameter, specified as a nonnegative real scalar in farads.
Data Types: double
Amplitude of the stimulus input to the transmitter analog model, specified as a real scalar.
Data Types: double
20%–80% rise time of the stimulus input to the transmitter analog model, specified as a positive real scalar in seconds.
Data Types: double
Single-ended resistance of the receiver analog model on the right side of the S-parameter, specified as a nonnegative real scalar in ohms.
Data Types: double
Single-ended impedance of the receiver analog model on the right side of the S-parameter, specified as a nonnegative real scalar in ohms.
Data Types: double
Option to acquire aggressor behavior, specified as:
same-load— The stimulus is applied to each aggressor input and probed at the victim output.same-source— The stimulus is applied to the victim input and probed at the aggressor output.
The same-load definition is more direct. But the
same-source definition is used by methodologies that rely on time
domain excitation, such as HSPICE, to stimulate the system with a single pulse or step
response.
Simultaneous Bi-Directional Architecture Style, specified as none
or ReplicaSummer.
Single-ended resistance of the receiver analog model on the left side of the S-parameter, specified as a nonnegative real scalar in ohms.
Data Types: double
Capacitance of the receiver analog model on the left side of the S-parameter, specified as a nonnegative real scalar in farads.
Data Types: double
Single-ended resistance of the transmitter analog model on the right side of the S-parameter, specified as a nonnegative real scalar in ohms.
Data Types: double
Capacitance of the transmitter analog model on the right side of the S-parameter, specified as a nonnegative real scalar in farads.
Data Types: double
Automatically detect port order.
This property is read-only.
Port order used for the S-parameter channel analysis, returned as a vector. If you
do not define the port order using PortOrder property, the through
paths are automatically detected and reported here.
Data Types: double
This property is read-only.
Impulse response of the system defined by the S-parameter channel object, returned as a vector.
Data Types: double
This property is read-only.
Time vector corresponding to the system impulse responses, returned as a vector.
Data Types: double
This property is read-only.
S-parameter frequencies, specified as a positive real-valued vector. The frequencies are sorted from the smallest to the largest value.
Data Types: double
This property is read-only.
Transfer function of the system defined by the S-parameter channel object, returned as a vector.
Data Types: double
This property is read-only.
Output statistics from rational (RF Toolbox), returned as an
object.
Data Types: double
This property is read-only.
Uncertainty due to rise time discretization, returned as a negative real scalar.
Data Types: double
Examples
Create an S-parameter channel object.
obj = SParameterChannel('FileName','default.s4p');
Extract the time vectors and impulse responses.
t = obj.t; impulse = obj.ImpulseResponse;
Plot the impulse response.
plot(t,impulse);

Version History
Introduced in R2021aDesign bidirectional links in the SerDes Simulink® models.
The SparameterChannel object now allows you to input a Touchstone 2.0 data file as an input argument.
See Also
rational (RF Toolbox) | Analog Channel | serdes.ChannelLoss
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