Unfortunately there's no real pattern. And it wasn't enough to make me think it was an essential part of any portal. But it wouldn't hurt to at least try.

It's my own design. I'll send you a copy of the schematics and the basic explanation.

[Sends some scanned notes. These are very similar to his plans for the Death Ray. They should be largely incomprehensible and there will be several inexplicable doodles of tropical fish in the margins.]