A slice may cause it to look more like an antenna than a solid plane. It depends greatly on the types and locations of current flowing through the ground plane. Regardless, it's a large enough plane that if you have a matching power plane, place several decoupling capacitors around (perhaps as part of normal decoupling), and the entire circuit is fairly low speed then I'd be surprised if you had any issues due to the ground plane design. If you want to experiment and can afford a few extra resistors, place the slit in the plane and place pads for a few zero ohm resistors to bridge the gap. Then you can put nothing in, shorting resistors, and even inductors or capacitors for testing to see what the best policy is. Let us know how it turns out! -Adam On 1/23/08, alan smith wrote: > I've got a square board, but with a circle routed out in the middle. Its about 200mm square, with a 100mm diameter circle. > > So, I'm thinking that its probably not a really good idea to have it be a solid ground plane, but for EMI purposes somwhere it should slice that plane so its not a complete loop and act as an antenna. > > Thoughts? > > > --------------------------------- > Never miss a thing. Make Yahoo your homepage. > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Moving in southeast Michigan? Buy my house: http://ubasics.com/house/ Interested in electronics? Check out the projects at http://ubasics.com Building your own house? Check out http://ubasics.com/home/ -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist