An HPM weapon transmits a very short, very powerful radio pulse that overloads electronics — a bit like a lightning strike close by. It does not need to aim precisely: everything in the beam takes the hit.
In practiceThat is why HPM is being developed mainly against drone swarms: one pulse can disable several drones at once, whereas a laser has to deal with them one by one. In tests, the American Leonidas system disabled several drones in one go this way.
An HPM weapon emits short, extremely powerful RF pulses that overload electronics. The energy gets in by two routes:
- Front door: through the antennas and sensors that are designed precisely to receive RF — the most direct route.
- Back door: through gaps, cables and wiring, which act as unintended antennas.
The big difference from the laser: HPM has a wide area of effect and does not need to be aimed exactly. That makes it ideally suited against swarms of drones or a cluster of electronics — one pulse can hit several targets at once. Examples are the CHAMP programme (a cruise missile with an HPM payload), the counter-swarm demonstrator THOR and commercial counter-UAS systems such as Epirus Leonidas.