%--------------------------------------------------------------------------
% Edited by bbl
% Date: 2024-03-23(yyyy-mm-dd)
% simplify eq
%--------------------------------------------------------------------------
function A = MA(R1, C1, w)
I = [      1,      0,       0,       0;
           0,      1,       0,       0;
           0,      0,       1,       0;
           0,      0,       0,       1;];
IC1 = [    0,      0,       0,       1;
           1,      0,       0,       0;
           0,      1,       0,       0;
           0,      0,       1,       0;];
IC2 = [    0,      1,       0,       0;
           0,      0,       1,       0;
           0,      0,       0,       1;
           1,      0,       0,       0;];
M11 =  (1/R1  +1i*w*C1)*I;
M12 = -(1/R1*I+1i*w*C1*IC1);
M21 =  (1/R1*I+1i*w*C1*IC2);
M22 = -(1/R1  +1i*w*C1)*I;
A12 = inv(M12);
A11 = -A12*M11;
A21 = M21-M22*A11;
A22 = M22*A12;
A   = [A11,A12;A21,A22];