# Zin of a Transmission Line Given ZL, Zo, l and f

1. Nov 20, 2012

### timeforplanb

1. The problem statement, all variables and given/known data
What is the input impedance in polar coordinates of 222.85 cm long 50 ohms line with a load of 20-j40 ohms at 300MHz?

2. Relevant equations
lambda=v/f
Znorm=ZL/ZO

3. The attempt at a solution
Plotting that in the SC:

Calculate wavelength: lambda=velocity/frequency=3x108/300x106
I know that using c as my velocity is wrong, but I'm completely lost so I did that in my quiz anyways. The answer we get from the above equation is 1, which is completely useless if we use that to rotate towards the generator because we'll arrive at the same point.

So what I need help with is knowing what the transmission line length (in cm) is for, and how we will find the wavelength given the data.