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Using ports in layout/schematic that are not part of model

Question asked by mahkoe on Jul 18, 2016
Latest reply on Sep 22, 2017 by bafisher


I think this might be a simple task, but even after two days I still can't figure out how to do it. So here goes:

 

I am trying to use ADS to design a power amp PCB. I am planning to use two stages, where each stage is a "black-box" amplifier (specifically, the TGA2535 and the TGA2624-CP from Qorvo). Qorvo published the S-Parameters files, which I am using to model the circuit. So here's the problem (using the TGA2535 as an example, datasheet here: http://www.triquint.com/products/d/DOC-A-00000829)

 

The circuit actually needs biasing, reference voltages, and other nice stuff that connects to the chip (which is in a QFN-24 5x5mm package), however, the model only makes use of the S-Parameters file, which simply connects from the RF-IN to RF-OUT. I drew up a nice QFN-24 footprint in layout, and later I'm gonna need to draw out the traces for all the biasing and sequencing circuits, which need to connect to the right pins on the TGA2535.

 

My schematic. Note that the "four leaf clovers" are because I couldn't duplicate the port to use on multiple connections to the layout

schem.PNG

My layout. Why is everything so huge? Shouldn't ADS have a nicer way to work with small footprints?

layout.png

Lastly, for completeness, here is the symbol I drew up for use in other parts of my workspace.

sym.PNG

 

 

All I want to do is add "dummy signals" to the circuit that connect to the layout, but do not actually affect the model! After all, I still need to draw up a PCB.

 

Bonus question: this chip actually uses the same signal on several pins. How do you do that on an SMD footprint that you've drawn yourself?

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