I am trying to plot Id Vs Vds of AlGaN HEMT. I have written the code but I am getting a straight line. Please check this code

clc;

clear all;

m=0.23; %#1%

q=1.6e-19;

d1=22e-7;

d2=1e-7;

fis=1.4*m+0.87;

deff=23.01e-7;

%detaEg=6.13*m+(1-m)*3.42-m*(1-m)+(m-1)*3.42;

detaEc=0.862*1.602e-19;

EA=10.31;

EF=2.1;

deta2deg=0.25*1.602e-19;

deff=d1+d2+deta2deg;

r1=q*EA/deff;

r2=fis+(EF-(detaEc)/q);

Esat=190*10^5;

vs=2.1*10^5;

mu=1380*10^-4;

z=100e-6;

r3=vs*Esat/sqrt(Esat^2+(vs/mu)^2);

vgs=2;

Vds=0:0.01:10;

Idsat=zeros(size(Vds));

m=length(Vds);

for i=1:m

Idsat(i)=r1.*(vgs-(r2)+Vds(i))*z*r3;

i=i+1;

end

xlabel('vds');

ylabel('Idsat');

plot(Vds,Idsat)

Answer 1

[sai charan sampara]

Hello Nudrat,

I understand that you are trying to plot the relation between variables “Id” and “Vds”. In the code mentioned above “Vds” is an array of values from 0 to 10 and “Idsat” is defined in a for loop as

Idsat(i)=r1.*(vgs-(r2)+Vds(i))*z*r3;  

In this equation the parameters “r1”, “vgs”, “r2”, “z”, “r3” are all scalars of constant value. Hence the relation between “Idsat” and “Vds” is of the form “Ids=m*Vds+c” which is the equation of a straight line. Hence the graph is correct with respect to the equations provided.

If the output is not as expected, then there might be an error in the equations governing the parameters or an error in the relation between the two variables.

You can recheck the equations and check whether there is any mistake or inconsistency in them. Also check if the variable you have plotted is the one you require.

I hope this helps.

Thanks,

Charan.