How top fix the code below

Hello,

I am new to the MATLAB RF toolbox. I need to set up an analysis of the cascading of three general trasmission lines.

I have this code which has some bugs I do not know how to fix.

Help would be appreciated

Thank you

% Initialize RF toolbox
clc;
clear;

% Define frequency range (1 GHz to 10 GHz)
f = linspace(1e9, 10e9, 201);  % Frequency points

% Create Transmission Line objects using 'rfckt.cascade'
% Specify characteristic impedance and electrical length for each transmission line

% Transmission Line 1
z0_1 = 50;           % Characteristic impedance (Ohms)
el_1 = 90;           % Electrical length (degrees)
tl1 = rfckt.txline('Z0', z0_1, 'StubMode', 'NotAStub', 'Termination', 'NotApplicable');
set(tl1, 'LineLength', el_1, 'Frequency', f, 'Analyzed', 'Analyzed');

% Transmission Line 2
z0_2 = 75;           % Characteristic impedance (Ohms)
el_2 = 45;           % Electrical length (degrees)
tl2 = rfckt.txline('Z0', z0_2, 'StubMode', 'NotAStub', 'Termination', 'NotApplicable');
set(tl2, 'LineLength', 'el', 'Frequency', f, 'Analyzed', 'Analyzed');

% Transmission Line 3
z0_3 = 100;          % Characteristic impedance (Ohms)
el_3 = 30;           % Electrical length (degrees)
tl3 = rfckt.txline('Z0', z0_3, 'StubMode', 'NotAStub', 'Termination', 'NotApplicable');
set(tl3, 'LineLength', 'el', 'Frequency', f, 'Analyzed', 'Analyzed');

% Cascade the transmission lines
cascaded_tl = rfckt.cascade('Ckts', {tl1, tl2, tl3});

% Analyze the cascading transmission line across the defined frequency range
analyze(cascaded_tl, f);

% Plot S-parameters of the cascaded transmission line
figure;
s_params = cascaded_tl.AnalyzedResult.S_Parameters;
rfplot(s_params, 'db', f);
title('S-Parameters of Cascaded Transmission Lines');
xlabel('Frequency (Hz)');
ylabel('Magnitude (dB)');

% Analyze Impedance, VSWR, and more
z_params = cascaded_tl.AnalyzedResult.Z_Parameters;
vswr = cascaded_tl.AnalyzedResult.VSWR;

figure;
plot(f, vswr);
title('VSWR of Cascaded Transmission Lines');
xlabel('Frequency (Hz)');
ylabel('VSWR');
grid on;

% Displaying results
disp('Impedance of the cascaded transmission lines:');
disp(z_params);

disp('S-parameters of the cascaded transmission lines:');
disp(s_params);

[Star Strider]

I am not certain what the correct argument would be here for your rfplot call (using ‘s_params’ is noi correct). I corrected as much as I could.

% Initialize RF toolbox
clc;
clear;

% Define frequency range (1 GHz to 10 GHz)
f = linspace(1e9, 10e9, 201);  % Frequency points

% Create Transmission Line objects using 'rfckt.cascade'
% Specify characteristic impedance and electrical length for each transmission line

% Transmission Line 1
z0_1 = 50;           % Characteristic impedance (Ohms)
el_1 = 90;           % Electrical length (degrees)
tl1 = rfckt.txline('Z0', z0_1, 'StubMode', 'NotAStub', 'Termination', 'NotApplicable');
set(tl1, 'LineLength', el_1, 'Freq', f);
analyze(tl1, f)

ans = 
   rfckt.txline with properties:

        LineLength: 90
          StubMode: 'NotAStub'
       Termination: 'NotApplicable'
              Freq: [201x1 double]
                Z0: 50.0000 + 0.0000i
                PV: 299792458
              Loss: 0
          IntpType: 'Linear'
             nPort: 2
    AnalyzedResult: [1x1 rfdata.data]
              Name: 'Transmission Line'

% Transmission Line 2
z0_2 = 75;           % Characteristic impedance (Ohms)
el_2 = 45;           % Electrical length (degrees)
tl2 = rfckt.txline('Z0', z0_2, 'StubMode', 'NotAStub', 'Termination', 'NotApplicable');
set(tl2, 'LineLength', el_2, 'Freq', f);
analyze(tl2, f)

ans = 
   rfckt.txline with properties:

        LineLength: 45
          StubMode: 'NotAStub'
       Termination: 'NotApplicable'
              Freq: [201x1 double]
                Z0: 75
                PV: 299792458
              Loss: 0
          IntpType: 'Linear'
             nPort: 2
    AnalyzedResult: [1x1 rfdata.data]
              Name: 'Transmission Line'

% Transmission Line 3
z0_3 = 100;          % Characteristic impedance (Ohms)
el_3 = 30;           % Electrical length (degrees)
tl3 = rfckt.txline('Z0', z0_3, 'StubMode', 'NotAStub', 'Termination', 'NotApplicable');
set(tl3, 'LineLength', el_3, 'Freq', f);
analyze(tl3, f)

ans = 
   rfckt.txline with properties:

        LineLength: 30
          StubMode: 'NotAStub'
       Termination: 'NotApplicable'
              Freq: [201x1 double]
                Z0: 100
                PV: 299792458
              Loss: 0
          IntpType: 'Linear'
             nPort: 2
    AnalyzedResult: [1x1 rfdata.data]
              Name: 'Transmission Line'

% Cascade the transmission lines
cascaded_tl = rfckt.cascade('Ckts', {tl1, tl2, tl3});

% Analyze the cascading transmission line across the defined frequency range
analyze(cascaded_tl, f);

% Plot S-parameters of the cascaded transmission line
figure;
s_params = cascaded_tl.AnalyzedResult.S_Parameters;
rfplot(s_params, 'db', f);

Error using rfplot (line 109)
Undefined function 'rfplot' for input arguments of type 'double'.

title('S-Parameters of Cascaded Transmission Lines');
xlabel('Frequency (Hz)');
ylabel('Magnitude (dB)');

% Analyze Impedance, VSWR, and more
z_params = cascaded_tl.AnalyzedResult.Z_Parameters;
vswr = cascaded_tl.AnalyzedResult.VSWR;

figure;
plot(f, vswr);
title('VSWR of Cascaded Transmission Lines');
xlabel('Frequency (Hz)');
ylabel('VSWR');
grid on;

% Displaying results
disp('Impedance of the cascaded transmission lines:');
disp(z_params);

disp('S-parameters of the cascaded transmission lines:');
disp(s_params);

.

[Pierre]

Thank you. will try

[Star Strider]

My pleasure!