freq=123e6;
om=2*pi*freq;
jom=j*om;
R1=0.2;
m=100;

L1=1e-9*linspace(10,100,m)';
c1=1e-12*linspace(0,50,m)';
L1_g=L1*ones(1,m); 
c1_g=ones(m,1)*c1';
Z_L=R1+jom*L1_g;
Y_L=1./(Z_L);
Z=1./(jom*c1_g+Y_L);
cterm=(om*c1_g.*abs(Z_L)).^2;
rZ=R1./(1+cterm);
real_value=real(Z); %[rZ(:) real(Z(:))], return
real_value=rZ;

% alles zeichnen
figure
mesh(1e9*L1_g,1e12*c1_g,real_value)
title('resonance tuning');
xlabel('L1 / nH');
ylabel('c1 / pF');
zlabel('real\_part');