What is my mistake in this MATLAB code?

[David83]

Hi,

I am trying to plot the AN product sec II.C in the attached paper as:

clear all
clc

s=0.5;
w=0;
d=5; 

f=0:20;

NdB1=(17-30.*log10(f));
N1=10.^(NdB1./10);
NdB2=40+20*(s-0.5)+26.*log10(f)-60.*log10(f+0.03);
N2=10.^(NdB2./10);
NdB3=50+7.5*w^0.5+20.*log10(f)-40.*log10(f+0.4);
N3=10.^(NdB3./10);
NdB4=-15+20.*log10(f);
N4=10.^(NdB4./10);

N=N1+N2+N3+N4;

adB=0.11.*((f).^2./(1+(f).^2))+44.*((f).^2./(4100+(f).^2))+2.75*10^-4.*(f).^2+0.003;
a=10.^(adB./10);

A=(d^(1.5)).*a.^d;



A_N=1./(A.*N);
 
A_NdB=10*log10(A_N);
 
plot(f,A_NdB)

where the details of these equations are highlighted in the attached file. But I get something not exactly the same as in Fig. 3. Why?

Thanks

View attachment MITSG_07-13J.pdf