I will be very happy if you can help me. I am trying to get the effective mu and epsilon values of the metamaterial unit cell. Although I am trying very hard, the values are inconsistent from the article. Can you help me? Thanks for your help. This is my code

clear all;

S11_gen = readtable('5g_s11_abs.txt'); % S11: frekans/Hz real

S11_phs = readtable('5g_s11_phs.txt'); % S11: frekans/Hz imag

S21_gen = readtable('5g_s21_abs.txt'); % S11: frekans/Hz real

S21_phs = readtable('5g_s21_phs.txt'); % S11: frekans/Hz imag

S11_phs2 = deg2rad(S11_phs{:,2});

S21_phs2 = deg2rad(S21_phs{:,2});

Frequency_S11 = S11_gen{:, 1}; % S11 frekans sütunu (Hz)

S11=S11_gen{:,2}.*(cos(S11_phs2)+1i*sin(S11_phs2));

Frequency_S21 = S21_gen{:, 1}; % S21 frekans sütunu (Hz)

S21=S21_gen{:,2}.*(cos(S21_phs2)+1i*sin(S21_phs2));

% Frekansların eşleştiğini kontrol etme

if ~isequal(Frequency_S11, Frequency_S21)

error('S11 ve S21 frekans sütunları eşleşmiyor! Lütfen dosyaları kontrol edin.');

end

% Frekans verisi (ortak frekans)

Frequency = Frequency_S11*1e9;

% NRW Algoritması

c = 3e8; % Işık hızı (m/s)

d = 0.27e-3; % Malzeme kalınlığı (m)

k0 = 2 * pi .* Frequency / c; % Dalga sayısı (1/m)

z=((((1+S11).^2)-S21.^2)./(((1-S11).^2)-S21.^2)).^0.5;

tmp=(z-1)./(z+1);

exp=S21./(1-S11.*tmp);

n=(imag(log(exp))-1i.*real(log(exp)))./(k0*d);

epsilon=n./z;

mu=n.*z;

% DNG (Double Negative) frekanslarını belirleme

DNG_indices = find(real(epsilon) < 0 & real(mu) < 0); % DNG koşullarını sağlayan indeksler

DNG_frequencies = Frequency(DNG_indices); % DNG frekansları (Hz)

% Sonuçları görüntüleme

disp('DNG Olunan Frekanslar (GHz):');

disp(DNG_frequencies / 1e9); % GHz cinsinden frekanslar

% Grafikler

figure;

subplot(2, 1, 1);

plot(Frequency / 1e9, real(epsilon), 'b', 'LineWidth', 1.5); hold on;

% plot(Frequency / 1e9, imag(epsilon), 'r', 'LineWidth', 1.5);

xlabel('Frequency (GHz)');

ylabel('Permittivity (\epsilon)');

legend('Real(\epsilon)', 'Imag(\epsilon)');

title('Effective Permittivity');

grid on;

subplot(2, 1, 2);

plot(Frequency / 1e9, real(mu), 'b', 'LineWidth', 1.5); hold on;

% plot(Frequency / 1e9, imag(mu), 'r', 'LineWidth', 1.5);

xlabel('Frequency (GHz)');

ylabel('Permeability (\mu)');

legend('Real(\mu)', 'Imag(\mu)');

title('Effective Permeability');

grid on;