Added K IIR lpf filter

scripts/filter_design/bode_compare_Ks_lpf_iir_q15_k.py

@@ -0,0 +1,42 @@
+import numpy as np
+import matplotlib.pyplot as plt
+
+def bode_mag_phase(Fs, K, n=4096):
+    """Return frequency, magnitude (dB), and phase (deg) for 1-pole IIR."""
+    alpha = 2.0 ** (-K)
+    a = 1.0 - alpha
+    w = np.linspace(0, np.pi, n)
+    ejw = np.exp(-1j * w)
+    H = alpha / (1 - a * ejw)
+    f = (w / (2 * np.pi)) * Fs
+    mag_db = 20 * np.log10(np.abs(H) + 1e-20)
+    phase_deg = np.unwrap(np.angle(H)) * 180 / np.pi
+    return f, mag_db, phase_deg
+
+if __name__ == "__main__":
+    Fs = 15e6
+    Ks = [10, 8, 6, 4]
+
+    fig, (ax_mag, ax_phase) = plt.subplots(2, 1, sharex=True, figsize=(8, 6))
+
+    for K in Ks:
+        f, mag_db, phase_deg = bode_mag_phase(Fs, K, n=32768)
+        ax_mag.semilogx(f, mag_db, label=f"K={K}")
+        ax_phase.semilogx(f, phase_deg, label=f"K={K}")
+
+    # ---- Styling ----
+    f_max = 40e3  # 40 kHz
+    ax_mag.set_xlim(10, f_max)         # start at 10 Hz for nicer log scaling
+    ax_mag.set_ylim(-60, 1)
+    ax_mag.set_title("Ideal Bode Response vs K")
+    ax_mag.set_ylabel("Magnitude [dB]")
+    ax_mag.grid(True, which='both')
+    ax_mag.legend()
+
+    ax_phase.set_xlabel("Frequency [Hz]")
+    ax_phase.set_ylabel("Phase [deg]")
+    ax_phase.grid(True, which='both')
+    ax_phase.set_xlim(10, f_max)
+
+    plt.tight_layout()
+    plt.show()