ABCBY ALEXANDER GEORGEARMED FORCES and law enforcement have
surprisingly few efective anti-drone tools,
and none—that are declassiied—to target
multiple unmanned aerial vehicles (UAVs),
or swarms. Shotgun shells that ire nets to
snare the propellers work only at close range.
Missiles, like the $38,000 Stinger, aren’t
cost-eicient for taking out $900 drones.
And high-power lasers and signal jammers
are efective but must be ixed on a target for
precious seconds before they disable a UAV.
But this spring, Raytheon released details
on a new type of drone defense using high-
power microwaves (HPM).
The same electromagnetic energy you
use to reheat chili can knock out drones
in less than a second. An HPM beam works
on the atomic level, passing through a
drone’s exterior and distorting the fragile
semiconductors that keep the drone aloft.
Once the target is in sight, a microsecond’s
worth of silent, invisible microwaves moves
at the speed of light, frying the circuits,
says Don Sullivan, a director at Raytheon
who worked on the HPM. And critically,
the beam can be manipulated into a cone
shape, creating an efective ield that can
knock out multiple UAVs with an energy
cost of less than $1 per kill.
The system is largely autonomous, detect-
ing, identifying, and tracking targets with
AESA (active electronically scanned array)
radar. It’s the same radar found on modern
ighter jets. AESA uses an array of thousands
of modules that change direction almost
instantaneously, detecting targets more
quickly and more accurately than an older
spinning-disc system or infrared systems
that might not pick up the minimal heat sig-
nature of a quadcopter. Though the HPM
system requires little human input, the order
to engage targets remains with its operator.
A / MORE
POWER,
FASTER
The microwave
beam’s pulse
relies on a
very high and
fast power
peak to crack
the crystal
structure of
semiconductors
beyond repair.B / PULSE
GUIDANCE
The disc and
tilting square
on top of the
HPM system are
reflectors
that aim the
microwave beam
at targets.C / DRONE
TRACKER
To track mul-
tiple targets
simultane-
ously, the HPM
uses a phased-
array radar
with sets of
antennas that
can be pointed
in different
directions.The Swarm Killer
The latest threat: swarms of unmanned aerial
vehicles designed to overwhelm their under-equipped
target. ISIS combatants abroad and hostage takers
in the United States have started using squadrons of
of-the-shelf drones to annoy, surveil, and even drop
munitions. But there’s a new way to ight back.
ILLUSTRATION BY TAVIS COBURN22 JULY/AUGUST _ 201 POPULARMECHANICS.COM
DEFENSE