Hello
As you see this problem with single stub matching
I matched zl=.5+1.5i to a normalized line (Z0=50)(I did it with smith chart and analytically) but as you see in the second picture as I calculate Zin it doesn't get me the same result (.5+1.5j).
what is my wrong?
The impedance of the shorted stub reduces to z_in = j*tan(2*pi*1.68) = j2.13.
The input impedance of the load as viewed from the stub is z_in = ((0.5+j1.5) + j(50Ω)*tan(2*pi*0.28))/((50Ω) + j(0.5+j1.5)*tan(2*pi*0.28)) = 0.21 - j4.49.
The two in parallel don't give 1... am I missing something?
I am a little confused. Why do you keep handwriting "Yin = Zin"? Yin is of course 1/Zin
and in computing the impedance where the stub joins the main line, the ADMITTANCES add, not the impedances. You want normalized Yin total to equal 1 at that point.