What power should I input in a Wilkinson combiner on FR4?

[zuzu]

Hi all,

Can anyone tell me what power should I insert maximum in a wilkinson combiner designed on FR4, 1.6mm material ? I try to combine back 4 modules of 250W each at 150MHz (so two will combine 250+250 and the third 500+500).

I also want to ask what power should be 100 ohm resitors during normally operation, need to know what to buy.

For splitting the signal, since I inject ~30W I plan to use the same wilkinson design on FR4 but for saving space and PCB I think to use lumped design... comments ?

Thanks in advance,
Edi

 

[vfone]

Re: Wilkinson on FR4

5W would be fine for the power of the 100 ohms resistor when you combine 250W, and 10W for 500W (the parasitic inductance of the resistor should be very low).
Beware to terminate correctly all ports when you combine powers using Wilkinson splitter, otherwise the 100 ohms resistor it will burn instantaneous.

 

[zuzu]

Re: Wilkinson on FR4

Ok, I'll use 150W resistor on Al cooler, I found non-inductive ones in Farnell. But how about power inserted in FR4. I saw a lot of FM broadcast transmitters with cheap combiners on FR4. Can I simmulate somehow temperature of microstrip agains power with ADS or Ansoft ? Apreciate any point of start.

 

[waseemsh]

Wilkinson on FR4

hi,
can you help me to design an "Microstrip wilkinson equal combiner of 50 W" and to simulate on ADS or Ansoft.

what PCB materials should be used.

Added after 1 minutes:

Frequency is 100 Mhz

 

[vamshikrishna]

Re: Wilkinson on FR4

Hi

u can design powerdivider in ADS simulator.

use sub 5880 ,31 mil to get better results.

1). use two 70.7 ohms in parlell and one isolated resistor of 100 ohms.