All this talk of jamming the 2.4Ghz ISM band is quite naive.
Firstly, drones also commonly communicate on the 433MHz and 900MHz ISM bands, which is much longer range, and some are capable of operating on the 5.6GHz bands.
Secondly, many of them are capable of completely autonomous operation by following a GPS
circuit. The drone that's pestering you may not even be transmitting to an operator, it may just be recording to an SD card and returning home. Finally, all of the new ones are capable of return-to-origin in the event that they lose communications
Thirdly, the vast majority of 2.4GHz signaling mechanisms are spread-spectrum, which means they automatically frequency hop to avoid noise
and channels that are already in use, because these bands are predicated on noisy use. If you don't know what spread-spectrum is, read the wikipedia article on it.
There is no "off-the-shelf" analog transmitter you could buy that can generate a broadband
signal across the entire 2.4GHz band. Consider that this band is almost 100MHZ wide--5X wider than the entire FM radio
band and vastly wider than the AM radio band. Generating a signal that broad takes a considerable amount of power--even Microwave ovens in that band aren't that wide.
Sure, you could build and power a broadband
2.4GHz jammer, and then you'd merely be breaking federal law. It's illegal in the U.S. to intentionally jam anything.
I spent six years in the Navy
as an Electronic Warfare technician--my job was jamming radar
. Since then I've been heavily involved in wireless networking, including monitoring and surveying the 2.4GHz spectrum on spectrum analyzers for field deployments.