Whether base or lid, it's usually a B/G antenna... Either type, have connections inside the case that can be modified. Most people do it themselves, but there are some computer repair places that do it (nothing cheap and off the shelf). The antenna connection comes off the card and goes thru the card connector, to whatever is internally setup by the manufacturer. The usually if to tap into that with a splitter/y connector, and put an external antenna adapter (usually mini uhf) on the back of the case. For generic external antennas (or a specific one tuned for A), that usually works out the easiest.