Doubts about project: Z optimum with load pull and matching to 50 ohms

[Caroline_Franca]

Hi, it's the first time I'm working with PAs and I have some doubts about the project. First, I did the load pull to find the optimum load (12+5*j), put the conjugate complex in the port (12-5*J) e with lumped components (using a capacitor and inductor) I did transformation to find 12+5*j in Z parameters. After that, I did impedance matching with T-Match high pass to 50 ohms.

So, I have in the output: L choker + 1 inductor and 1 capacitor of optimum load + 1 inductor and 2 capacitors of impedance matching. (In the end Inductor:3, Capacitor:3).

In the end I found the correct PAE, Pout, Gain e etc like in my load-pull simulations (ADS). But I have a lot components. I don't know if this is the right method to find the Z optimum and after that match with 50 ohms.

 

[chuckey]

If you do a T match network for 12 to 50 ohms ( 3 components). Then you can adjust your input L to remove 5j from it. It could turn into a capacitor!
Frank

 

[Caroline_Franca]

Can you explain more? Dou you say about the L of the transformation to optimum load? I think I have too much inductors in my circuit, but to transform the output of the PA to the optimum load I had to use one Inductor with a capacitor because when I changed to real components it was impossible with just the capacitor to have 12 +5j (because of the limits of the size).