close all
clear all
%frequency range
f=[0.1:0.2:10000];
%Circuit elements values
Res=1e3;
cap=1e-6;
% Capacitor's impedance
i=sqrt(-1);
ZCap=1./(i*2*pi*f*cap);

% Transfer function (TF)
H=ZCap./(Res+ZCap);
Phase=angle(H);
Amp=abs(H);

% Semi log plot of Amplitude of TF
figure(1)
hold on;
subplot(2,1,1)
semilogx(f,20*log10(Amp),'b');
grid on
title('Log magnitude of TF')
xlabel('Frequency [Hz]')
ylabel('dB Magnitude [dB]')

% Semi log plot of Amplitude of TF (manual)
figure(2)
hold on;
subplot(2,1,1)
plot(log10(f),20*log10(Amp),'b');
xticks(log10([[0.1:0.1:1] [2:1:10] [20:10:100] [200:100:1000] [2000:1000:10000]]));
X_Label=[{'0.1'} repmat({''},1,8) {'1'} repmat({''},1,8) {'10'} repmat({''},1,8) {'100'} ...
    repmat({''},1,8) {'1000'} repmat({''},1,8) {'10000'}];
xticklabels(X_Label)
grid on
title('Log magnitude of TF')
xlabel('Frequency [Hz]')
ylabel('dB Magnitude [dB]')

% Semi log plot of Phase of TF
figure(1)
subplot(2,1,2)
semilogx(f,Phase.*180/pi,'r')
grid on
title('Phase of TF')
xlabel('Frequency [Hz]')
ylabel('Phase [Degrees]')

% Semi log plot of Phase of TF (manual)
figure(2)
subplot(2,1,2)
plot(log10(f),Phase.*180/pi,'r')
xticks(log10([[0.1:0.1:1] [2:1:10] [20:10:100] [200:100:1000] [2000:1000:10000]]));
xticklabels(X_Label)
grid on
title('Phase of TF')
xlabel('Frequency [Hz]')
ylabel('Phase [Degrees]')