%variables
R_f = 3.6e3; % Total Resistance [ohms] of the fluid 
R_m = 2e3; %Resistance [ohms] of the membrane
C_m = 5.6e-11; % Capacitance [farads] of the membrane

%C_m = e*A/d = 8*e0*(200 um^2)(50 nm) = 56pF (silicon nitride membrane, solid)
%R_f = 2x branches of p*d/A

f = logspace(-2,9,500); %frequency Scan (.01 to 1e6 hz)
Z_m = R_m./(1i*2*pi*R_m*C_m.*f+1); % Impedence of the membrane (RC circuit)
Z_tot = R_f + Z_m; %total circuit behavior
%%
figure,

subplot(2,1,1)
plot (f,log10(abs(Z_tot))); %log impedance
set(gca,'xscale','log')
set(gca,'yscale','log')
xlabel('Frequency [Hz]')
ylabel('Impedance [dB]')
title('Bode Plot');



subplot(2,1,2)
plot (f,(180/pi)*angle(Z_tot));
set(gca,'xscale','log')
xlabel('Frequency [Hz]')
ylabel('Phase [Degrees]')
title('Phase Plot');
% set(gca,'yscale','log')