diff --git a/src/SAR3Q19.m b/src/SAR3Q19.m
new file mode 100644
index 0000000000000000000000000000000000000000..eb223581b19c656d075a362391cf9f0d85fd3f0e
--- /dev/null
+++ b/src/SAR3Q19.m
@@ -0,0 +1,25 @@
+clear; clc;
+
+Fe = 44100;
+K = 10;          
+N = 10000;       
+
+% Def de h_r(k)
+hr = ones(1, K) / K;
+
+% FFT de h_r
+H = fft(hr, N);
+H_mag = abs(H(1:N/2)) / max(abs(H));  % On normalise
+H_db = 20 * log10(H_mag + eps);       % dB
+
+% Axe des fréquences en Hz
+f = linspace(0, Fe/2, N/2);
+
+% Affichage
+figure;
+plot(f, H_db, 'b', 'LineWidth', 1.5);
+xlabel('Fréquence (Hz)');
+ylabel('|H_r(f)| en dB');
+title('Réponse en fréquence du filtre de retour h_r(k)');
+grid on;
+ylim([-60 5]);