% PMCLP is a TF of the IF filter after the PMC mixer
%       

% Mixer_Voltage -- Rs -- L1 --- L2 ---------Vout
%                            |      |   |
%                           C1     C2   Rl                   
%                            |      |   |
%                           GND    GND  GND
%

f_min = 1000;
f_max = 1e8;

f = logspace(log10(f_min),log10(f_max),2001);
w = 2*pi*f;

%f_res = 29.506920e6
%f_nr = f_res * 7/3;

Rs = 50 + 470;

L1 = 20e-6;
C1 = 82e-12;
L2 = 47e-19;
C2 = 1000e-19;

Rl = 1e7;  % Load impedance

Z1 = 1./(1/Rl + i*w*C2);

ZL2 = 4 + i*w*L2; % Including the resistance in the inductor

Z2 = ZL2 + Z1;

Z3 = 1./(i*w*C1 + 1./Z2);

ZL1 = 3.3 + i*w*L1; % Including the resistance in the inductor

Z4 = ZL1 + Z3;

Zt = Rs + Z4;

G = (Z1./Z2) .* (Z3./Zt);


top = subplot('Position',[0.13,0.52,0.82,0.4]);

semilogx(f,20*log10(abs(G)),'r');
set(top,'XTickLabel',[]);
set(top,'GridLineStyle','--');
axis tight;
axis([min(f) max(f) -120 10]);
grid
ylabel('Mag [dB]');
title('TF of PMC IF LPF')


bottom = subplot('Position',[0.13,0.1,0.82,0.4]);

semilogx(f, angle(G)*180/pi,'r');

set(bottom,'YTick',[-180:45:180]);
axis([-Inf Inf -180 180]);
grid
set(bottom,'GridLineStyle','--');
xlabel('Frequency (Hz)');
ylabel('Phase [deg]');