mimo2t.m

经典书籍MIMO Signals And Systems的源代码

% Program "mimo2t.m"

% Implementation of Node Reduction Algorithm.
% Calculates impedances of node-equivalent 
% T-shaped two-port network.

% Input Parameters:
% - Number of internal and exterior nodes: P
% - Admittances connecting nodes

P = 1;

while P < 2;
  P = input('Number of Nodes P = ');

   if P < 2
     disp('Specify more nodes!')
   end;
end;

% Input of admittances connecting nodes
disp('Make sure off-diagonal elements have negative sign')
disp(' ')

for k=1:P;
   for n=k:P;

	if k==n;
	 disp('Admittance of'), disp(n), disp('th node');
	 Y(k,n)=input('Y(k, n) = ');
	else	
    disp('Admittances connecting nodes'),disp(k),disp(n);
    Y(k,n)=input('Y(k, n) = ');
    Y(n,k)=Y(k,n);
	end;

    end;
end;
% ===============

Yr=Y;

% Calculation of reduced admittance matrix, Yr
for k=1:P-2;   
   Yr=Yr(1:P-k,1:P-k)-Yr(1:P-k,P+1-k)*Yr(P+1-k,1:P-k)/Yr(P+1-k,P+1-k);
end;
% ===============

disp(' ')
disp('Original Admittance Matrix:'),Y
% disp('Reduced Admittance Matrix:'),Yr

y2=-Yr(1,2); y1=Yr(1,1)-y2; y3=Yr(2,2)-y2;

% Calculation of reduced impedance matrix, Zr, of T circuit
disp(' ')
 if det(Yr)==0
  disp('Impossible to calculate reduced impedance matrix Zr')
  exist=0;

  else
   disp('Reduced two-port T-circuit impedance matrix Zr ')
   Zr=inv(Yr)
   z2=Zr(1,2); z1=Zr(1,1)-z2; z3=Zr(2,2)-z2;
   exist=1;
 end;
% ==================  

if exist;
 disp('Impedances of equivalent two-port T-circuit')
  z1, z2, z3
end;