GTOM
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There are already jammer rifles directed at drones.trurle said:Spark gap do extra-thermal emission at RF; most of RF generation of spark is due current instabilities ans tails off at about 400-500 MHz. The cutoff frequency is actually have to do with air pressure, not feeding voltage/current. Lower harmonics can extend the jamming band roughly to 1.3 GHz.
Regarding "brute force" jamming, it do not work well with LTE (4G) commlinks. LTE tolerate by standard 0.3 mW of in-band interference per antenna. With typical 5 cm patch antennas, tolerance is 0.12 W/m2. With typical heavy-track based military jammer having 30 kW output, the effective (omnidirectional) jamming is achieved at distance 140 meters. Or may be even 5-15m meters if drone use a MIMO antenna array. This number shows it is pretty difficult to jam a large swarm of drones.