Lady Ada has posted detailed docs and pics of her Wave Bubble Portable RF Jammer. Like everything else this kick ass lady hacker does, this project is, well, kick ass!
This pics shows two versions, an early one with external rubber duckies (left) which has an effective range of 20′. and the final v1.0 model, with internal antenna. that hides inside of a ciggie pack (and offers less reach as a trade-off). Output power is .1W (high bands) and .3W (low bands). A rechargeable, internal Li-on batt offers up to four hours of ops, depending on number of bands jammed.
The WaveBubble is self-tuning and can jam many frequencies at the same time. A USB port allows you to plug the Wave Bubble into a PC to program new RF bands to jam.
Limor does her typical exemplary job of offering detailed docs, photos, parts lists, and even downloadable CAD, PCB (Gerber files), and schematics. But sadly, this is not a beginner or even intermediate project, as there is a lot of tiny surface mount components here. And no, she won’t make and sell you one and will not be offering a kit, as cellphone and other RF jamming is generally frowned upon by the FCC.