Electromagnetic weapon

Electromagnetic weapons are a type of directed energy weapons which use electromagnetic radiation to deliver heat, mechanical, or electrical energy to a target to cause pain or permanent damage. They can be used against humans, electronic equipment, and military targets generally, depending on the technology.

When used against equipment, directed electromagnetic energy weapons can operate similarly to omnidirectional electromagnetic pulse (EMP) devices, by inducing destructive voltage within electronic wiring. The difference is that they are directional and can be focused on a specific target using a parabolic reflector. Faraday cages may be used to provide protection from most directed and undirected EMP effects.

High-energy radio frequency weapons (HERF) or high-power radio frequency weapons (HPRF) use high intensity radio waves to disrupt electronics.

High Power Microwave devices use microwave radiation, which has a shorter wavelength than radio.

Development
In the United States of America, the University of Texas-Austin Institute for Advanced Technology (IAT) conducts basic research to advance electrodynamics and hypervelocity physics related to electromagnetic weapons.

Use against humans
Generally considered 'non-lethal weapons', electromagnetic weaponry do however pose health threats to humans. In fact, "non-lethal weapons can sometimes be deadly."

Some common bio-effects of electromagnetic or other non-lethal weapons include effects to the human central nervous system resulting in physical pain, difficulty breathing, vertigo, nausea, disorientation, or other systemic discomfort, as weapons not directly considered lethal can indeed cause cumulative damage to the human body.

Project Pandora, conducted by the Walter Reed Army Institute of Research, WRAIR, included externally induced auditory input from pulsed microwave audiograms of words or oral sounds which create the effect of hearing voices that are not a part of the recipients own thought processes. Microwave pulses can also affect the epidermis (skin) and dermis, the thick sensitive layer of skin and connective tissue beneath the epidermis that contains blood, lymph vessels, sweat glands, and nerve endings, generating a burn from as far as 700 yards.

Examples

 * MEDUSA (weapon)
 * Active Denial System

Crop Circles
A beam of radiation, if used in conjunction with a computer, can theoretically render the extremely complex patterns observed in genuine crop circles. Dr Levengood, a biophysicist of BLT Research Team and Ken Larsen, a biologist, have concluded that the way in which the stalks are flattened without being broken or damaged is typical of microwave radiation coming from a plasma source. Microwave radiation is not only invisible to the naked eye but can also penetrate clouds and account for the effects caused on crops. The most conspicuous of these effects are elongations of stems, abnormal holes at the nodes and bending of the plant at the nodes. Microwaves heat the water stored in plants. The water turns into vapor, expands, and finally escapes to the surrounding air. Having lost all water content, plant cells undergo plasmolysis and thus the structural integrity of the entire plant is severely undermined to the extent that it can no longer support its own weight.

Use against equipment
Directed energy weapons such as Boeing’s Airborne Laser which can be mounted on a 747 jet is able to burn the skin off enemy missiles.

Electromagnetic weapons, including high power microwaves, were used during the Gulf War to disrupt and destroy the enemy's electronic systems and may have been used for other effects. Types and magnitudes of exposure to electromagnetic fields is unknown.