.: High-Power Microwave Energy as Weapon :. 

High-power electromagnetic pulse generation techniques and high-power microwavetechnology have matured to the point where practical e-bombs (electromagneticbombs) are becoming technically feasible, with new applications in both strategicand tactical information warfare. The development of conventional e-bomb devicesallows their use in nonnuclear confrontations. This chapter discusses aspects of thetechnology base and weapon delivery techniques and proposes a doctrinal foundationfor the use of such devices in warhead and bomb applications.1 Brief biography ofDr. Carlo Kopp is presented in footnote at the end of this chapter.

Introduction

High-power microwave (HPM) [1, 2] sources have been under investigation forseveral years as potential weapons for a variety of combat, sabotage, and terroristapplications. Due to classification restrictions, details of this work are relatively unknown outside the military community and its contractors. A key point to recog-nize is the insidious nature of HPM. Due to the gigahertz-band frequencies(4–20 GHz) involved, HPM has the capability not only to penetrate radio frontends, but also for the most minute shielding penetrations throughout the equipment.At sufficiently high levels, as discussed, the potential exists for significant damage todevices and circuits. For these reasons, HPM should be of interest to the broadspectrum of EMC practitioners.

Electromagnetic pulse (EMP) and high-powered microwave (HMP) [1] weaponsoffer a significant capability against electronic equipment susceptible to damage bytransient power surges. This weapon generates a very short, intense energy pulseproducing a transient surge of thousands of volts that kills semiconductor devices.The conventional EMP and HMP weapons can disable non-shielded electronicdevices including practically any modern electronic device within the effectiverange of the weapon.

Weapon of electrical mass destruction is based on high-power electromagneticpulse (EMP) [3] generation techniques and high-power microwave technology.

Weapons that direct energy instead of matter on targets have undergone extensiveresearch in the last two decades. They have two potential advantages over existingweapon systems. First, they use a power supply rather than a magazine of explosivemunitions; this “deep magazine” is unlikely to be expended in battle. Second, theyattack at the speed of light, 160,000 times faster than a bullet, thus making avoidanceof the incoming bolt impossible and negating the advantage of increasingly swifttactical missiles.

Directed energy weapons (DEW) generally fall into three categories:

1. High-power lasers

2. Microwave or radio-frequency (RF) energy weapons

3. Charged particle beam weapons

High-power microwave (HPM) [1, 2] has an advantage over the other DEWs inthat microwave does not face a serious propagation issue. Particle beams and lasershave difficulties in propagating through the atmosphere (thermal blooming in case ofthe laser), and electron beams cannot propagate in space. Moreover, both arepinpoint weapons with small spot sizes requiring precise pointing to hit the target.Antenna-directed microwave, on the other hand, spreads through diffraction and hasspot size large enough to accommodate some lack of precision in pointing andtracking. Lasers and particle beams are also much less electrically efficient, morecomplex, and therefore costlier.

The electromagnetic bomb or e-bomb is another form of a weapon of massdestruction. The e-bomb takes advantage of how we rely so heavily on electricity.It is designed to not just disable but also destroy electronic devices by sending out anelectromagnetic pulse or an EMP. An EMP is a burst of electromagnetic radiationfrom an explosion; the resulting electric and magnetic fields merge with electronicsystems to produce catastrophic currents and voltage surges. An EMP is a form ofelectromagnetic induction as this is the production of voltage. If an e-bomb were toexplode it alters the magnetic flux lines of the earth meaning that the North will not be as affected but the East, South, and West will experience the blast if you will. Thiswould mean thousands of volts of electromagnetic energy from the highest positivesto the highest negative polarities transferred via air and powerlines. This is animportant weapon to have in a war as it can take out your opponent’s form ofcommunication.

High-Power Microwave

The prosecution of a successful information warfare (IW) campaign against anindustrialized or a postindustrial opponent will require a suitable set of tools. Asdemonstrated in the Desert Storm air campaign, air power has proven to be a mosteffective means of inhibiting the functions of an opponent’s vital informationprocessing infrastructure. This is because air power allows concurrent or parallelengagement of a large number of targets over geographically significant areas.

While Desert Storm demonstrated that the application of air power was the mostpractical means of crushing an opponent’s information processing and transmissionnodes, the need physically to destroy these with guided munitions absorbed asubstantial proportion of available air assets in the early phase of the air campaign.Indeed, the aircraft capable of delivery of laser-guided bombs were largely occupiedwith this very target set during the first nights of the air battle.

The efficient execution of an IW campaign against a modern industrial orpostindustrial opponent will require the use of specialized tools designed to destroyinformation systems. Electromagnetic bombs built for this purpose can provide,where delivered by suitable means, a very effective tool for this purpose.

E-Bomb

An e-bomb (electromagnetic bomb) is a weapon that uses an intense electromagneticfield to create a brief pulse of energy that affects electronic circuitry without harminghumans or buildings. At low levels, the pulse temporarily disables electronicssystems; midrange levels corrupt computer data. Very high levels completelydestroy electronic circuitry, thus disabling any type of machine that uses electricity,including computers, radios, and ignition systems in vehicles. Although not directlylethal, an e-bomb would devastate any target that relies upon electricity: a categoryencompassing any potential military target and most civilian areas of the world aswell. According to a CBS News report, the United States deployed an experimentale-bomb on March 24, 2003, to knock out Iraqi satellite television and disrupt thebroadcast of propaganda.

In the United States, most e-bomb research has been carried out at the Air ForceResearch Laboratory at Kirtland Air Force Base in New Mexico, where researchershave been exploring the use of high-power microwaves (HPM). Although the devices themselves may be relatively uncomplicated to manufacture (PopularMechanics illustrated a simple design in September 2001), their usage poses anumber of problems. To create an effective e-bomb, developers must not onlygenerate an extremely high-powered pulse of energy but also find a way to controlboth the energy—which can behave in unpredictable ways—and the heat generatedas its by-product. Furthermore, for nonnuclear e-bombs, the range is limited.According to most defense analysts’ speculations, devices in development are likelyto affect an area of only a few hundred yards.

The concept behind the e-bomb arose from nuclear weaponry research in the1950s. When the US military tested hydrogen bombs over the Pacific Ocean,streetlights were blown out hundreds of miles away and radio equipment wasaffected as far as away as Australia. Although at the time these effects wereconsidered incidental, since that time researchers have sought a means of focusingthat energy.

The Electromagnetic Pulse Effect (EMP)

The electromagnetic pulse (EMP) effect was first observed during the early testing ofhigh-altitude airburst nuclear weapons. The effect is characterized by the productionof a very short (hundreds of nanoseconds) but intense electromagnetic pulse, whichpropagates away from its source with ever-diminishing intensity, governed by thetheory of electromagnetism. The electromagnetic pulse is in effect an electromag-netic shock wave.

This pulse of energy produces a powerful electromagnetic field, particularlywithin the vicinity of the weapon burst. The field can be sufficiently strong toproduce short-lived transient voltages of thousands of volts (i.e., kilovolts) onexposed electrical conductors, such as wires, or conductive tracks on printed circuitboards, where exposed.

It is this aspect of the EMP effect, which is of military significance, as it can resultin irreversible damage to a wide range of electrical and electronic equipment,particularly computers and radio or radar receivers. Subject to the electromagnetichardness of the electronics, a measure of the equipment’s resilience to this effect, andthe intensity of the field produced by the weapon, the equipment can be irreversiblydamaged or in effect electrically destroyed. The damage inflicted is not unlike thatexperienced through exposure to close proximity lightning strikes, and may requirecomplete replacement of the equipment, or at least substantial portions thereof.

Commercial computer equipment is particularly vulnerable to EMP effects, as itis largely built up of high-density metal oxide semiconductor (MOS) devices, whichare very sensitive to exposure to high-voltage transients. What is significant aboutMOS devices is that very little energy is required to permanently wound or destroythem; any voltage typically in excess of tens of volts can produce an effect termedgate breakdown, which effectively destroys the device. Even if the pulse is notpowerful enough to produce thermal damage, the power supply in the equipment

will readily supply enough energy to complete the destructive process. Woundeddevices may still function, but their reliability will be seriously impaired[4, 5]. Shielding electronics by equipment chassis provides only limited protection,as any cables running in and out of the equipment will behave very much likeantennae, in effect guiding the high-voltage transients into the equipment.

Computers used in data processing systems, communications systems, displays,industrial control applications including road and rail signaling, and those embeddedin military equipment, such as signal processors, electronic flight controls, anddigital engine control systems, are all potentially vulnerable to the EMP effect.

Other electronic devices and electrical equipment may also be destroyed by theEMP effect. Telecommunications equipment can be highly vulnerable, due to thepresence of lengthy copper cables between devices. Receivers of all varieties areparticularly sensitive to EMP, as the highly sensitive miniature high-frequencytransistors and diodes in such equipment are easily destroyed by exposure to high-voltage electrical transients. Therefore, radar and electronic warfare equipment,satellite, microwave, UHF, VHF, HF, and low-band communications equipmentand television equipment are all potentially vulnerable to the EMP effect.

It is significant that modern military platforms are densely packed with electronicequipment, and unless these platforms are well hardened an EMP device cansubstantially reduce their function or render them unusable.