def plot_lf_ideal_pn_full(div_jit, pn_dco, pn_dco_df, kdco, fclk, _type, m, n, k, fz, fp, delay,
b1, b2, steps=100, fmin=1e1, fmax=1e7, *args, **kwargs):
df = fmax/steps
freqs = np.geomspace(fmin, fmax, int(steps))
lf_params = dict(_type=_type, k=k, fz=fz, fp=fp, delay=delay)
# a = pll_otf2(freqs, M, N, KDCO, KP, FZ, FP, DELAY)
g = pll_tf(freqs, _type, k, fz, fp, delay)
# g = a/(1+a)
kpn = pn_dco*pn_dco_df**2
ndco = np.abs(1-g)**2*kpn/freqs**2
ndco[np.where(g==1)] = 0
# ndco = min_ro_pn(fclk*n, freqs, pn_dco, pn_dco_df)*np.abs(1-g)**2
ntdc = tdc_pn(fclk, n, m, g)
# ntdc = tdc_pn(fclk, n, g, 1/float(m*fclk))
nlf = lf_pn(freqs, fclk, lf_params, kdco, b1, b2)
ndiv = div_pn(fclk, n, div_jit, g)
plt.semilogx(freqs, 10*np.log10(ntdc), label="TDC")
plt.semilogx(freqs, 10*np.log10(ndco), label="DCO")
plt.semilogx(freqs, 10*np.log10(nlf), label="Loop filter")
plt.semilogx(freqs, 10*np.log10(ndiv), label="Divider")
plt.semilogx(freqs, 10*np.log10(ndco+ntdc+nlf+ndiv), label="Total")
plt.legend()
plt.grid()
plt.title("SSB Phase noise")
plt.xlabel("Frequency [Hz]")
plt.ylabel("Phase noise [dBc]")
def var_ntdc_post_lf(lf_params, steps=513):
fclk = lf_params["fclk"]
freqs = np.linspace(0, fclk / 2, steps)
g = pll_tf(freqs, **lf_params)
ntf_tdc_lf = (lf_params["n"] / lf_params["m"]) * (2j * np.pi * freqs /
lf_params["kdco"]) * g
return 2 * scipy.integrate.romb(
abs(ntf_tdc_lf)**2 * (1 / (12 * fclk)), 0.5 * fclk / steps)
def plot_pll_tf(k, fz, fp, _type, delay, steps=100, fmax=1e7, *args, **kwargs):
freqs = np.geomspace(1, fmax, int(steps))
g = pll_tf(freqs, _type, k, fz, fp, delay)
# g = a/(1+a)
plt.subplot(1,3,1)
plt.semilogx(freqs, 20*np.log10(np.abs(g)), label="G(f)")
plt.semilogx(freqs, 20*np.log10(np.abs(1-g)), label="1-G(f)")
plt.legend()
plt.grid()
plt.title("Closed loop responses")
plt.xlabel("Frequency [Hz]")
plt.ylabel("Gain [dB]")
def plot_loop_filter(pn_dco, pn_dco_df, fclk, _type, m, n, k, ki, fz, fp, delay, bw,
a0, a1, b0, b1, b2, mode="tdc", sigma_ph=0.1, steps=100, fmax=1e7,
*args, **kwargs):
freqs = np.geomspace(1, fmax, int(steps))
# a = pll_otf2(freqs, M, N, KDCO, KP, FZ, FP, DELAY)
g = pll_tf(freqs, _type, k, fz, fp, delay)
# g = a/(1+a)
kpn = pn_dco*pn_dco_df**2
plt.subplot(1,3,1)
# plt.semilogx(freqs, 20*np.log10(np.abs(solpf(freqs, fn, damping))), label="Ideal")
plt.semilogx(freqs, 20*np.log10(np.abs(g)), label="G(f)")
plt.semilogx(freqs, 20*np.log10(np.abs(1-g)), label="1-G(f)")
plt.legend()
plt.grid()
plt.title("Closed loop responses")
plt.xlabel("Frequency [Hz]")
plt.ylabel("Gain [dB]")
plt.subplot(1,3,2)
# ndco = min_ro_pn(fclk*n, freqs, pn_dco, pn_dco_df)*np.abs(1-g)**2
ndco = np.abs(1-g)**2*kpn/freqs**2
ndco[np.where(g==1)] = 0
# ntdc = tdc_pn(fclk, n, g, 1/float(m*fclk))
if mode is "tdc": ntdc = tdc_pn(fclk, n, m, g)
if mode is "bbpd": ntdc = bbpd_pn(fclk, n, sigma_ph, g)
plt.semilogx(freqs, 10*np.log10(ntdc), label="TDC")
plt.semilogx(freqs, 10*np.log10(ndco), label="DCO")
plt.semilogx(freqs, 10*np.log10(ndco+ntdc), label="Combined")
plt.legend()
plt.grid()
plt.title("SSB Phase noise")
plt.xlabel("Frequency [Hz]")
plt.ylabel("Phase noise [dBc]")
plt.subplot(1,3,3)
w, h = scipy.signal.freqz([a0, a1], [b0, b1, b2], fs=fclk)
_h = lf(w[1:], _type, ki, fz, fp)
plt.title("Ideal versus discrete loop filter")
plt.xlabel("Frequency [Hz]")
plt.ylabel("Gain [dB]")
plt.semilogx(w[1:], 20*np.log10(np.abs(h[1:])), label="Discrete")
plt.semilogx(w[1:], 20*np.log10(np.abs(_h)), label="Ideal")
plt.grid()
plt.legend()
def plot_tdc_pn(pn_dco, pn_dco_df, fclk, _type, m, n, k, ki, fz, fp, delay, bw,
a0, a1, b0, b1, b2, steps=100, fmax=1e7, label="",
*args, **kwargs):
freqs = np.geomspace(1, fmax, int(steps))
# a = pll_otf2(freqs, M, N, KDCO, KP, FZ, FP, DELAY)
g = pll_tf(freqs, _type, k, fz, fp, delay)
# g = a/(1+a)
ntdc = tdc_pn(fclk, n, m, g)
# ntdc = tdc_pn(fclk, n, g, 1/float(m*fclk))
plt.semilogx(freqs, 10*np.log10(ntdc), label="TDC %s"%label)
plt.legend()
plt.grid()
plt.title("SSB Phase noise")
plt.xlabel("Frequency [Hz]")
plt.ylabel("Phase noise [dBc]")
def plot_dco_pn(pn_dco, pn_dco_df, fclk, _type, m, n, k, ki, fz, fp, delay, bw,
a0, a1, b0, b1, b2, steps=100, fmax=1e7, label="",
*args, **kwargs):
freqs = np.geomspace(1, fmax, int(steps))
# a = pll_otf2(freqs, M, N, KDCO, KP, FZ, FP, DELAY)
g = pll_tf(freqs, _type, k, fz, fp, delay)
# g = a/(1+a)
kpn = pn_dco*pn_dco_df**2
# ndco = min_ro_pn(fclk*n, freqs, pn_dco, pn_dco_df)*np.abs(1-g)**2
ndco = np.abs(1-g)**2*kpn/freqs**2
ndco[np.where(g==1)] = 0
plt.semilogx(freqs, 10*np.log10(ndco), label="DCO %s"%label)
plt.legend()
plt.grid()
plt.title("SSB Phase noise")
plt.xlabel("Frequency [Hz]")
plt.ylabel("Phase noise [dBc]")
def pow_ntdc_post_lf(freqs, lf_params, fclk, steps=513):
g = pll_tf(freqs, **lf_params)
ntf_tdc_lf = (lf_params["n"] / lf_params["m"]) * (2j * np.pi * freqs /
lf_params["kdco"]) * g
return abs(ntf_tdc_lf)**2 * (1 / (12))