ADS beginners question

Hi,
I'm just a beginner in ADS. Im using the version ADS 2009 & currently working in board level RF circuits.
As a first example i would like to build a simple Low pass filter in ADS.I build it using ideal components & obtained the S11 & S21 parameters.
Now i need to replace my capacitors with ATC type & inductors with coil craft type. Then i need to generate a Layout using that schematics..

But i've not that much idea in how to work with PCB inside ADS.
I've got a design kit from coil craft and installed the same..

Now i can add schematic symbols by selecting the appropriate palette. But when i try to generate layout inside ADS..its saying SMT_pad not defined using default pad dimensions..

further reading i understood that if i define an SMT_Pad element it will be used to generate the layout..Its is ok for me incase of resistors & caps like 0603 ,0805 etc dimensions

My question is whether the coil craft models doesn't include the layout dimensions.?? OR shall i ve to create an SMT pad all the time..?

Then how to do with other common packages like say SOT23,SC70 etc .?


or In short Can somebody tell me hows the procedure in ADS from schematic to layout in case of SMD components..
Thanks,

Those design kits do not include pattern information. You can draw it by hand using layout tool but you can not simulate it using its 2,5D solver. My recommendation is that use ADS just for schematic level simulations and draw layout in a more advanced layout tool like Altium, Mentor or Cadence.

Hmm.. But then can you please tell me how to include the board level parasitics of traces in your simulation..
Im pretty familiar with Altium & Allegro,Have been using it for board layout for a long time..but for RF circuits, i thought ADS could do schematics simulation & can do a layout simulation as well..Im i wrong??

You are right. You can simulate your layout using ADS. As far as I know you may include the S-parameters of the devices you add into your layout and simulate but I have never tried it. My way of including parasitics is to introduce parasitic capacitances and inductances, that I expect, as discrete elements into my schematic but to be honest this way still needs optimizations after implementation.

What u can do it just do u layout at ADS
simulate with momentum and them with
looks alike take this block to schematic than add to u pad spar of capacitors and inductors and that's it

Ok..Im a little confused...Can somebody please explain..

Okie i ve done schematics in ADS.Now i generate/update layout in ADS.It puts default components in ADS Layout..
Now can some body tell me how to replace the default footprints with correct ones like that we do in any layout tool like allegro or altium

If you mean that you want to add the layout effects to your simulation, you should draw those footprints by yourself in momentum, define a substrate for it, put ports for the connections and then simulate only layout in momentum.

remember that you are able to simulate only layout in momentum. Your layout will have some ports. Then you can import S parameters of this layout in the schematic and connect the models of capacitors and inductors or whatever you have in schematic to this snp data item.

Any assistance of pcb when you complete design,please kindly contact Email: Jane@kingsunpcb.com .

Thank you Hamid..

I think now i got the idea..do layout in ADS..leave vacant spaces for SMD components & add ports for their connectivity..simulate the layout..carry back to schematics..in the layout look like fashion right?So i can do momentum cosimulation in schematics..
Thank you very much.

themaccabee said:

Thank you Hamid..

I think now i got the idea..do layout in ADS..leave vacant spaces for SMD components & add ports for their connectivity..simulate the layout..carry back to schematics..in the layout look like fashion right?So i can do momentum cosimulation in schematics..

Click to expand...

Yes, that's right. But actually if your layout is fixed and your not going to modify it, you don't need to create layout look-alike components. Just simulate the layout and import its SNP to the schematic.
Basically if your design frequency is like below 10 GHz or so, modifying footprints of SMT packages is not needed in most cases.