%This program is want to simulate the characterisitic of Chireix power
%amplifier which based on the Z-matrix of the Chireix combiner
%2007-02-22
%Sweden
%wujianfeng
zo=50;
p1max=100;
p2max=100;
N=100;
zload=1;
BO=6;

zt=sqrt(zload*zo/2);
vmax=sqrt((p1max+p2max).*(2*zload));
vout=[0:vmax/(N-1):vmax];

vtent=vmax.*10^(-BO/20);
vdd=30;
%err=vtent-vdd*sin(th)*zt/(0.5*zo*zload*sin(2*th)+zt^2);
options=optimset('MaxIter',500,'TolFun',0.001);
th1=acos((2*zload/zt)*(vtent/vmax)*sqrt(1-(vtent/vmax)^2));
[th]=fminsearch(@err,th1,options);
%th=acos((2*zload/zt)*(vtent/vmax)*sqrt(1-(vtent/vmax)^2));
Fi=acos(-vout).*cos(th).*zo./(zt*2*vdd);
I1=-j*vdd*tan(th).*exp(j*Fi)/zo-zt.*vout./(zload.*zo.*cos(th));
I2=j*vdd*tan(th).*exp(-j*Fi)/zo-zt.*vout./(zload.*zo.*cos(th));
I3=-vout/zload;
II=vdd*sin(th).^2/(0.5*zo*zload*sin(2*th)+zt^2);

Fimax=atan(2/(sin(2*th)))*180/pi;

vtent2=2*zt*30*cos(atan(-2/sin(2*th)))/(cos(th)*zo);
vtent=vdd*sin(th)*zt/(0.5*zo*zload*sin(2*th)+zt^2);
index=find(vout>=vtent);
index2=find(vout>=vtent2);
I1(1:index2(1))=[0:index2(1)-1].*I1(index2(1))./(index2(1)-1);
I1(1:index(1))=[0:index(1)-1].*II./(index(1)-1);
I2(1:index2(1))=[0:index2(1)-1].*I2(index2(1))./(index2(1)-1);
I2(1:index(1))=0;
% x=[index(1)+1:index2(1)];
% f=(x-x(1))./max(x-x(1));
% I2(index(1)+1:index2(1))=I2(index(1)+1:index2(1));
% I2(index(1)+1:end)=I2(index(1)+1:end);
z=[j*zo/tan(th) 0 -j*zt/sin(th);0 -j*zo/tan(th) j*zt/sin(th);-j*zt/sin(th) j*zt/sin(th) 0];
V=z*[I1;I2;I3];
V1=V(1,:);
V2=V(2,:);
V3=V(3,:);
Z1=V1./I1;
Z2=V2./I2;