def capacitor_v_divider():
"""1.2.2 Capacitor voltage divider"""
f = np.arange(1, 10000)
C1, R1 = C(1e-6), R(1e3)
RC = CircuitImpedance([R1, C1])
divider = VoltageDivider(C1, RC)
semilogx(f, divider.response(2*pi*f), "b-", linewidth=2)
ylabel(r"$V_{out}/V_{in}$", fontsize=18)
xlabel(r"$f$ $(Hz)$", fontsize=18)
xticks(fontsize=14)
yticks(fontsize=14)
show()
def RC_filters():
"""1.3.1 RC filters expected responses"""
f = np.arange(1e4, 1e6, 1e2)
C1, R1 = C(1e-6), R(1.6)
highpass = VoltageDivider(C1, R1)
lowpass = VoltageDivider(R1, C1)
semilogx(f, highpass.response(2*pi*f), "b-", linewidth=2, label="High-pass filter")
semilogx(f, lowpass.response(2*pi*f), "r-", linewidth=2, label="Low-pass filter")
ylabel(r"$V_{out}/V_{in}$", fontsize=18)
xlabel(r"$f$ $(Hz)$", fontsize=18)
xticks(fontsize=14)
yticks(fontsize=14)
legend(loc=3)
show()
def final_lowpass():
"""1.7 Bandpass plot for low pass at end of FM reciever"""
f = np.arange(10, 1e9, 1e4)
C1, R1 = C(1e-9), R(1e3)
lowpass = VoltageDivider(R1, C1)
semilogx(f, lowpass.response(2*pi*f), "b-", linewidth=2)
ylabel(r"$V_{out}/V_{in}$", fontsize=18)
plot([1.045e6, 1.045e6], ylim(), "r--", linewidth=2, label=r"FM Carrier $1.045 MHz$")
plot([20, 20], ylim(), "g:", linewidth=2, label=r"Audible $(20Hz-20kHz)$")
plot([20e3, 20e3], ylim(), "g:", linewidth=2)
xlabel(r"$f$ $(Hz)$", fontsize=18)
xticks(fontsize=14)
yticks(fontsize=14)
# ticklabel_format(axis='x', style='sci', scilimits=(-2,2))
legend(loc=3)
show()
def bandpass_plot():
"""1.7 Bandpass plot for our actual FM reciever values"""
f = np.arange(100000, 10000000, 1000)
L1, C1, R1 = L(1e-6), C(10e-9), R(27.)
Resistors = CircuitImpedance([R1, R1])
LC_loop = CircuitImpedance([L1, C1, C1, C1])
bandpass = VoltageDivider(Resistors, LC_loop)
plot(f, 20*log10(bandpass.response(2*pi*f)), "b-", linewidth=2)
# format plot with slightly weird bounds for aesthetic reasons
xlim(680000, 1320000)
ylim(-5, ylim()[1] + .05)
# plot(xlim(), [.5, .5], "m-", label="half power")
ylabel(r"Gain $(dB)$", fontsize=18)
plot([1.045e6, 1.045e6], ylim(), "r--", label=r"$1.045 MHz$", linewidth=2)
plot([1.045e6-100e3, 1.045e6-100e3], ylim(), "r:", label=r"$\pm100 kHz$", linewidth=2)
plot([1.045e6+100e3, 1.045e6+100e3], ylim(), "r:", linewidth=2)
xlabel(r"$f$ $(Hz)$", fontsize=18)
xticks(fontsize=14)
yticks(fontsize=14)
ticklabel_format(axis='x', style='sci', scilimits=(-2,2))
legend(loc=1)
show()
