exercise 6.1

f1=.5e8;f2=1.5e9;

Nf=10000          % amount frequency points between f1 f2        df=abs(f1-f2)/(Nf+1)               % frequency resolution

f=[f1:df:f2];

       

RLoad=2.5;Rgen=2.5;

L1=50e-9;C1=.79e-12;

       

ZRLoad=RLoad;ZL1=L1*1j*2*pi*f;ZC1=1./(1j*2*pi*f*C1);

Zgen=Rgen;

       

Zin=ZRLoad+ZL1+ZC1;

Z0=Zgen

       

Gamma_in=(Zin-Z0)./(Zin+Z0);

absGamma_in=abs(Gamma_in)

       

hp1=plot(f,absGamma_in);grid on

xlabel('f');ylabel('|\Gamma|')

hp1.Parent.XTick=linspace(f1,f2,5)

hp1.Parent.YTick=linspace(0,1,5)

  

 

 [min_Gamma nf0]=min(absGamma_in)

       

hold on

plot(f(nf0),min_Gamma,'rd')

       

f0=f(nf0)                                  % resonance frequency

IL_f0=min_Gamma                 % Insertion Loss

       

Comparing with direct calculation of resonant frequency:

       

1/(2*pi)*1/(L1*C1)^.5

       

Q0_series=1/(2*pi*f0*Rgen*C1)  % unloaded Q simple series tank

       

2*pi*f0*L1/Rgen

       

Qe_series=2*pi*f0*L1/RLoad

       

QLoad=1/(1/Q0_series+1/Qe_series)