Simulation of Wilkinson combiner in ADS momentum

[crayon]

ads momentum simulation resistor

Hi, I am working on a CPW wilkinson combiner. I get confused about the port types to use. Should I use differential or internal? ( on strips ). And I want to use thin film resistor as the isolation resistor. Where should I simulation them, in the layout or schematic(co-simulation)? THank you.

 

[iamdrew]

wilkinson combiner ads momentum

I think that you have it set up pretty good, I would just change a couple things. First, for the ports, go into the port editor, and assign the ground ports to "ground reference" ports, and then link them to your signal ports.

Second, I would draw the physical resistor in Momentum, and then just add the resistor layer to your substrate file, and assign what ever corresponding sheet resistance you are going to use. I have found that it simulates much better using that method, and can accurately measure the phase delay through the resistor.

Last, since you are doing a coplanar Wilkinson, and using asymmetrical line lengths, there is a great method of adding asymmetrical slots into your signal lines, which can significantly reduce the physical size of your splitter. I was able to get the 90 degree lines down to ~30 degrees or so. There is a good IEEE paper on it, I just can't recall the name right now.

Added after 1 minutes:

Sorry, I didn't catch it at first, I would also add a little more length to the outputs, and have both ground references.

Good Luck!

 

[kspalla]

I think there should be inner ground spread too as there is outer gnd.