8 way unequal wilkinson power divider design in AWR

hi folks..........

i m designing an unequal 8 way(2 way 3 stage) wilkinson power divider. i referred Pozar text book. I got a problem while designing 3rd stage. The problem is that i m getting high branch impedance ( around 300ohm) at last stage. While i m trying to calculate the length and width using AWR transmission calculator, it is saying invalid parameters, has to reduce impedance value.

I successfully designed 8 way equal wilkinson power divider and 4 way unequal wilkinson power divider. But i got struck at 8 way.

Plz do reply a solution for that problem. View attachment 5[/ATTACH][/ATTACH]3405[/ATTACH]

Hello Rajendra,

Yes, I went through your problem & found the following…
With the Substrate data you are using I think it is very difficult to get 328 Ohm Microstrip line trace
As I calculated using some free tool it shows that W is too small to fabricate or may not be possible with your process what you have ( I got W= 0.0013 mm from **broken link removed** )

Hence the error message in AWR Transmission Line Calculator (Txline), saying it is practically difficult to realize…

The solution is to use lower Dielectric Constant & Thicker Substrate material such as RT-duroid/RT-duroid5880 (Er=2.2, h=3.175 mm, t=70 um) Which may give impedance around 275 ohms around for W=0.01 mm
Then you have to re-calculate all the Microstrip line for this new substrate….

See the picture below


---manju---

I got the solution. We can keep impedance as 50 ohm for the next stage instead of taking previous stage impedance. Then we wont get high impedance values