SParameterChannel

Convert S-parameter to impulse response

Since R2021a

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

Syntax

obj = SParameterChannel(filename)

Description

obj = SParameterChannel(filename) creates an S-parameter channel object obj by importing data from the Touchstone file specified by filename.

Input Arguments

filename — Touchstone data file

character vector | string scalar

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

FileName — Name of Touchstone data

default.s4p (default) | character vector | string scalar

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

PortOrder — Port order for S-parameter

[] (default) | character vector

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

MaxNumberOfPoles — Maximum number of poles to use to fit rational model

1000 (default) | positive scalar integer

Maximum number of poles to use to fit a rational model, specified as a positive scalar integer.

Data Types: double

ErrorTolerance — Desired error tolerance for rational model fit

−40 (default) | real scalar

Desired error tolerance for rational model fit, specified as a real scalar in dB.

Data Types: double

SampleInterval — Sample interval of impulse response

6.2500e-12 (default) | positive real scalar

Sample interval of the impulse response, specified as a positive real scalar in seconds.

Data Types: double

StopTime — Desired duration of impulse response

1.0000e-07 (default) | positive real scalar

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

TxR — Single-ended impedance of transmitter analog model

50 (default) | nonnegative real scalar

Single-ended impedance of the transmitter analog model, specified as a nonnegative real scalar in ohms.

Data Types: double

TxC — Capacitance of transmitter analog model

1.0000e-13 (default) | nonnegative real scalar

Capacitance of the transmitter analog model, specified as a nonnegative real scalar in farads.

Data Types: double

TxAmplitude — Amplitude of stimulus input

1 (default) | real scalar

Amplitude of the stimulus input to the transmitter analog model, specified as a real scalar.

Data Types: double

TxRiseTime — 20%–80% rise time of stimulus input

1.0000e-11 (default) | positive real scalar

20%–80% rise time of the stimulus input to the transmitter analog model, specified as a positive real scalar in seconds.

Data Types: double

RxR — Single-ended impedance of receiver analog model

50 (default) | nonnegative real scalar

Single-ended impedance of the receiver analog model, specified as a nonnegative real scalar in ohms.

Data Types: double

RxC — Capacitance of receiver analog model

2.0000e-13 (default) | nonnegative real scalar

Single-ended impedance of the receiver analog model, specified as a nonnegative real scalar in ohms.

Data Types: double

PortOrderUsed — Port order used for S-parameter channel analysis

Read-only: vector

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

ImpulseResponse — System impulse response

Read-only: vector

This property is read-only.

Impulse response of the system defined by the S-parameter channel object, returned as a vector.

Data Types: double

t — Time vector

Read-only: vector

This property is read-only.

Time vector corresponding to the system impulse responses, returned as a vector.

Data Types: double

f — S-parameter frequencies

Read-only: positive real valued vector

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

TransferFunction — System transfer function

Read-only: vector

This property is read-only.

Transfer function of the system defined by the S-parameter channel object, returned as a vector.

Data Types: double

RationalResults — Output statistics

Read-only: object

This property is read-only.

Output statistics from rational (RF Toolbox), returned as an object.

Data Types: double

RiseTimeUncertainty — Uncertainty due to rise time discretization

Read-only: negative real scalar

This property is read-only.

Uncertainty due to rise time discretization, returned as a negative real scalar.

Data Types: double

Examples

Impulse Response from S-Parameter

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 R2021a

R2023b: Input Touchstone 2.0 data file in SparameterChannel object

The SparameterChannel object now allows you to input a Touchstone 2.0 data file as an input argument.