With rogue nations such as North Korea developing intercontinental ballistic missiles systems (ICBMs) able to reach North America, the U.S. government is showing new interest in using high-powered radio frequency microwave weapons (HPMs) to disable them.

The editors at High Frequency Electronics magazine recently focused on researchers with the U.S. Air Force Research Laboratory's (AFRL’s) Directed Energy Directorate at Kirtland Air Force Base, Albuquerque, New Mexico. The term "directed energy" connotes both light-based, high-energy laser weapons (HELs), as well as HPMs.

The magazine's editorial notes that AFRL scientists "have reiterated previously revealed work" on an HPM system known as the Counter-electronics High-Power Microwave Advanced Missile Project (CHAMP).

Thanks to the verbal fireworks and mud-slinging between President Donald Trump and North Korean dictator Kim Jong Un, interest in the world's strategic weapons generally — and, in particular, nuclear and directed energy weapons — is understandably growing quickly.

At trade publications like High Frequency Electronics, HPMs have received increased attention. A mid-decade story there entitled "Far Field Wireless Energy Transfer" addressed HPMs' theoretical potential. Another recent story gave the cause of a construction crane's failure as its boom's resonance with a nearby radio station antenna. Finally, another item noted the "mysterious sounds from an electronic organ due to a nearby mechanically scanning experimental defense radar."

Air Force scientists and others have extrapolated from such incidental evidence, as well as from other findings, to conclude that close-by HPMs can disrupt electronic circuits. They presume that a system like CHAMP can eventually be relied upon to disable missile launch systems, since close-proximity HPMs can cause semiconductors to breakdown and fail — due to intense thermal secondary breakdown from an HPM weapon's high-output transient electromagnetic waves.

Yet the Air Force's HPM weaponization program has been ongoing for more than 20 years. Boeing and Raytheon, the principal contractors on the continued research project, have not shown much (at least openly). In 2013, in battle zones such as Iraq and Afghanistan, certain ground-based air defense HPM systems and their emitters neutralized improvised explosive devices (IEDs) and unmanned aerial vehicles (drones).

It would be quite a leap for CHAMP to disable ICBMs and their systems, whether they're housed in large-scale subterranean launch silos or, more likely, perched atop wheeled, highly mobile and camouflaged surface-launchers. It's obvious: It will be tough to deliver a powerful microwave transmitter, much less its associated prime power source, to a location proximate to an enemy's own weapon.

Still, the Air Force research lab was able to

  • distill its counter-weapon into credible, usable form by fitting an HP microwave emitter onto an air-launched cruise missile (ALCM);
  • launch the missile from a B-52 bomber over the Utah Test & Training Range (UTTR) in 2012;
  • "detonate" the emitter on targets meaningfully analogous to those of an Air Force strategic sortie — mockups of buildings housing communications and computer systems, simulating an enemy missile installation as closely as possible.

Indeed, CHAMP budget documents told of targets fairly representing a variety of WMD production equipment types found in both North Korea and Iran.

The results? The Air Force developers were actually very pleased: The bomber- and missile-borne, air-launched RF HP-emitter, true to its purpose, shutdown computers their monitors went dark. Even the cameras monitoring the test succumbed to the emitter's potent radio waves.

Overall, the knockout punch affected a multitude of target classes. The developers predicted which ones, they said, with 100 percent accuracy.

But they also acknowledged that any CHAMP delivery vehicle would have to get fairly "close" to its target, and that would be difficult: The bane of radio waves like these, intended to deliver kinetic, if not knockout, energy, is attenuation (aka free-space path loss).

The applicable rule of physics: The power of such microwaves like CHAMP decreases by a quarter for every doubling of the distance within which the system is intended to operate. So, there's a horrendous obstacle to an RF-HPM emitter, even before considering dissipative factors like atmospheric absorption, hardware imperfections and antenna gain (the changeable shape of the optimal area in which an antenna can send or receive signals).

Of course, additional tests and experiments designed to enhance or advance the CHAMP system followed the 2012 and 2013 tests (evidently the only ones to have been declassified so far). The program continues to develop ever-more potent and nimble power sources, which lately prompted the Air Force to dub one such source, tested and used to upgrade the existing system, "SuperCHAMP."

Meanwhile, mid-decade, the program also nominated the low-flying Lockheed Martin AGM-158 Joint Air-to-Surface Standoff Missile, Extended Range (JASSM-ER), as the best air vehicle to carry the CHAMP payload. According to the HFE story, in January 2016, an AFRL document deemed JASSM-ER officially capable of entering contested areas and disabling an enemy's electronic systems without necessarily causing collateral damage.

In a speech later, Gen. Herbert "Hawk" Carlisle confirmed that such HPM weapons — some utilizing the missile as a carrier had been stockpiled for use on a "contingency" basis. Still, while the lab has managed some nominal milestones, the system may hardly be ready for the prime-time mission of neutralizing an adversary's ICBM on its launch device.

But at least such a system is no longer a pie-in-the-sky concept.