tparameters

Create T-parameter object

Syntax

tobj = tparameters(filename)

tobj = tparameters(tobj_old,z0)

tobj = tparameters(rftbx_obj)

tobj = tparameters(hnet, z0)

tobj = tparameters(paramdata,freq,z0)

Description

tobj = tparameters(filename) creates a T-parameter object, ht by importing data from the Touchstone file specified by filename. All data is stored in real/imag format.

tobj = tparameters(tobj_old,z0) converts a T-parameter data in tobj_old to the new impedance z0. z0 is optional, and if not provided, tparam_data is copied instead of converted.

tobj = tparameters(rftbx_obj) extracts S-parameter network data from rfdata.network object, an rfdata.data object, or any analyzed network object, and then converts the data to T-parameter data.

tobj = tparameters(hnet, z0) converts the network parameter data in hnet into T-parameter data.

tobj = tparameters(paramdata,freq,z0) creates T-parameter object directly from the specified data, paramdata using specified frequency and impedance.

Examples

Convert File to T-Parameters

Read S-parameter data from a Touchstone file and convert the data to T-parameters

T1 = tparameters('passive.s2p');
disp(T1)

  tparameters with properties:

      Impedance: 50
       NumPorts: 2
     Parameters: [2×2×202 double]
    Frequencies: [202×1 double]

Change Impedance of T-Parameters

Change the impedance of T-parameters to 100 ohms.

T1 = tparameters('passive.s2p');
disp(T1)

  tparameters with properties:

      Impedance: 50
       NumPorts: 2
     Parameters: [2×2×202 double]
    Frequencies: [202×1 double]

T2 = tparameters(T1,100); 
disp(T2)

  tparameters with properties:

      Impedance: 100
       NumPorts: 2
     Parameters: [2×2×202 double]
    Frequencies: [202×1 double]

Input Arguments

tobj_old — T-parameter object

scalar handle

T-parameter object, specified as a scalar handle.

paramdata — Input T-parameter data

2N-by-2N-by-K array of complex numbers

Input T-parameter data, specified as 2N-by-2N-by-K array of complex numbers (since R2023a). The function uses this input argument to set the value of the Parameters property of ht.

filename — Touchstone data file

character vector

Touchstone data file, specified as a character vector. filename can be the name of a file on the MATLAB^® path or the full path to a file.

Example: ht = tparameters('defaultbandpass.s2p');

freq — T-parameter frequencies

vector of positive real numbers

T-parameter frequencies, specified as a vector of positive real numbers. The frequencies are sorted from smallest to largest. The function uses this input argument to set the value of the Frequencies property of ht.

z0 — Reference impedance

50 (default) | positive real scalar | positive real vector

Reference impedance in ohms, specified as one of the following:

• Positive real scalar when you want the reference impedance of all ports of the network to be equal.

• Positive real vector of length N when you want the reference impedance of each port of the N-port network to be different. (since R2023a)

• Positive real vector of length K when you want the reference impedance of each of the K frequencies of the data to be different. (since R2023a)

If the reference impedance is a vector and the number of ports N equals the number of data frequencies K, N == K, then the sparameters object will assign each element of the vector to each port of the network. To specify reference impedances for each frequency in this case, specify Z0 as a 3-D vector of length 1-by-1-by-K.

You cannot specify Z0 if you are importing data from a file. The argument Z0 is optional and is stored in the Impedance property.

hnet — Network parameter data

scalar handle

Network parameter data, specified as a scalar handle. If hnet is a T-parameter object, then tobj is a deep copy of hnet. Otherwise, the function performs a network parameter conversion to create tobj. Specify hnet as one of the following types: sparameters, yparameters, gparameters, hparameters, zparameters, or abcdparameters.

rftbx_obj — network object

scalar handle

Network object, specified as a scalar handle. You can specify rftbxobj as one of the following types: rfdata.data object, rfdata.network object, or as any analyzed rfckt type.

Output Arguments

tobj — T-parameter object

scalar handle

T-parameter data, returned as a scalar handle. disp(ht) returns the properties of the object:

• NumPorts — Number of ports, specified as an integer. The function calculates this value automatically when you create the object.

• Parameters — T-parameter data, specified as a 2N-by-2N-by-K array of complex numbers (since R2023a). The 2N-by-2N T-parameter data is specified for each frequency in the “Frequencies” property. The function sets this property from the filename or paramdata input arguments.

• Impedance — Characteristic impedance used to measure the T-Parameters, specified as a numeric positive real scalar.

• Frequencies — T-parameter frequencies, specified as a K-by-1 vector of positive real numbers sorted from smallest to largest. The function sets this property from the filename or freq input arguments.

Version History

Introduced in R2015a

R2023b: Recommended over rfdata.network

tparameters is recommend over rfdata.network because it enables you to calculate T-parameters for a circuit object, an RF data, and a network.

R2023a: Enhancements to T-parameters function

The tparameters function now allows you to specify a:

• Vector of reference impedances in z0 when you want to specify a different reference impedance for each port in the N-port network.

• 2N-by-2N-by-K array of complex numbers as an input.