diff --git a/wide vs narrow/test_equal_RCS.m b/wide vs narrow/test_equal_RCS.m
new file mode 100755
index 0000000..e2c72bc
--- /dev/null
+++ b/wide vs narrow/test_equal_RCS.m	
@@ -0,0 +1,36 @@
+clc; clear; close all;
+
+run("../parameters.m");
+
+global f_c N_narrow N N_wide numP f_s N_high betas_wide delta_R_wide c;
+f_c = f_c * 1e3;
+
+numP = 1;
+s_T_wide = zeros(1, N * numP);
+
+for j = 1:numP
+    idx = ((j - 1) * N + (1:N_wide));
+    tp = idx / f_s;
+    s_T_wide(1, idx) = exp(1j * 2 * pi * f_c * tp);
+end
+
+s_R_wides = zeros(N_wide, N_wide * numP);
+
+for k = 1:N_wide
+    s_R_wides(k, :) = [zeros(1, k), s_T_wide(1:end - k)];
+end
+
+echo_1 = zeros(1, N * numP);
+
+for i = 1:10
+    echo_1 = echo_1 + betas_wide(i) * s_R_wides(i, :);
+end
+
+equal_beta = 0 + 0j;
+
+for i = 1:10
+    equal_beta = equal_beta + betas_wide(i) * exp(1j * 2 * pi * 2 * delta_R_wide * i / c);
+end
+
+fprintf("理论等效RCS: " + string(equal_beta) + "\n");
+fprintf("验证等效RCS: " + string(echo_1(50)) + "\n");