Extracting PCB strays from CAD

We have used Sonnet Lite to analyze arbitrary geometries when the simple things like Saturn weren't enough.

Phil Hobbs snipped-for-privacy@electrooptical.net wrote in news: snipped-for-privacy@electrooptical.net:

I think there are programs which are made to examine and design circuits like phased array radars, etc. that do such types of analysis. Very expensive stuff though.

Siemens CAD package Solid Edge now does PCB layout. They may have some analytics incorporated, but I do not have that version yet and still only do mechanicals with mine. But they have done PCBs now for a few years in their same CAD package. They also have machine wiring layout, which is where it got started. It is a very comprehensive CAD package with FEA, etc. so their layout tools may have some analytical functions incorporated.

Are there not also other solutions to examine? If it only 1 to 4 layers, you could use 0.032.

Another alternative would be a ceramic or alumina substrate or such.

Actually, at 500 MHz on a small board, only capacitance (and its df) should matter. One wavelength is 2 feet.

Yes, but I forget the name. But any 3D EM FEM modeler program will do.

As Larkin mentioned, at 500 MHz, you can still use lumped-component models, not needing solution of PDEs.

Joe Gwinn

Calculating node capacitance could still be tricky, with shapes and fringing and layers and vias and such. Bootstrapping makes it more interesting.

It's using microwave transistors.

Cheers

Phil Hobbs

There are method-of-moments codes that can do it with no big issue, such as FastCap and FastHenry.

I just found

We shall see.

Thanks

Phil Hobbs

The problem there is getting device models, especially lead inductances.

Yup. Fortunately Avago published really detailed package models, so I just use those.

Cheers

Phil Hobbs