Electromagnetic Defense: High-Power Disruptions (HPEM) and Intentional Interference (IEMI)

As modern warfare increasingly incorporates advanced technology, electromagnetic warfare has emerged as a pivotal domain. The techniques of jamming (signal blocking) and spoofing (signal deception) allow militaries to gain an edge by disrupting enemy communications, navigation, and targeting systems. In this article, we focus on two technical aspects of electromagnetic warfare: high-power electromagnetic (HPEM) disruptions and intentional electromagnetic interference (IEMI).

High-Power Electromagnetic Disruptions (HPEM): A Drone’s Achilles Heel

The rise of unmanned aircraft systems (UAS), or drones, has added new dimensions to both civilian and military applications. However, their dependency on sensitive electronics—often designed for civilian standards—makes them vulnerable to high-power electromagnetic (HPEM) attacks.

Understanding HPEM Technology

HPEM systems emit electromagnetic waves potent enough to disrupt drone electronics. This interference can result in malfunctioning control systems, erratic behavior, or complete shutdowns, neutralizing threats without physical destruction.

Applications in Military Defense

Military research facilities, such as the Fraunhofer Institute for Technological Trend Analysis in Germany, have pioneered HPEM testing to safeguard critical installations from drone threats. Field simulations evaluate HPEM weapon ranges and impacts, effectively protecting military bases, power grids, and infrastructure by targeting drone avionics.

Recent advancements highlight sophisticated HPEM sources capable of generating high-power microwave and ultrawideband signals. These tools are engineered to interfere with or damage electronic systems, posing significant risks to critical infrastructures.

In the U.S., the 101st Airborne Division’s experiments with surveillance and attack drones, decoys, and remotely-operated jammers signify a new era in electromagnetic warfare. Fort Johnson’s trials focus on enhancing battlefield efficiency while employing advanced defense mechanisms like fiber-optic cables, decoy devices, and robotic systems to secure command posts.

Intentional Electromagnetic Interference (IEMI): Threats Beyond the Battlefield

While HPEM focuses on disabling individual devices, intentional electromagnetic interference (IEMI) can disrupt entire systems. This technique involves broadcasting high-powered signals to overload or damage critical infrastructure, such as communication networks, power grids, and hospital equipment.

How it Works

IEMI attacks use strong electromagnetic pulses to interfere with electronic components within a system. Depending on the distance and the power of the attack, this disruption can cascade through interconnected systems, causing widespread malfunctions.

Real-World Scenarios

IEMI is particularly concerning for urban areas and industrial facilities, where uninterrupted electronic communication is critical. For example:

• Disrupting a data center’s operations could compromise critical information.
• Interfering with hospital systems could endanger lives reliant on medical devices.
• Targeting power grids could result in widespread blackouts.

To mitigate these risks, research is underway to develop robust detection systems that monitor electromagnetic signals for unusual interference. These systems not only issue warnings but also help locate and quantify the source of the disturbance, enabling faster response times and more effective countermeasures.

Innovations in Defending against Dual Threats of HPEM and IEMIE

To counter the dual threats of HPEM and IEMI, current defenses include electromagnetic shielding, such as Faraday cages and surge protection systems, as well as layered redundancies in critical networks. Current approaches include:

• Signal Monitoring and Detection: Advanced spectrum analysis tools detect interference patterns, enabling rapid counteractions.
• Shielding and Hardening: Conductive polymers and metallic barriers provide robust electromagnetic shielding.
• Standardization Efforts: IEEE’s "Recent Developments in High Power EM (HPEM) Standards" outline protective environments and testing methods for mitigating threats like High Altitude Electromagnetic Pulse (HEMP) and IEMI.
• Alternative Navigation Systems: Inertial navigation systems offer reliable alternatives to GPS, safeguarding operations against spoofing and jamming.
• Decentralized Infrastructure Models: By decentralizing power grids and communication networks, nations reduce the impact of localized IEMI attacks.

Organizations like Fraunhofer INT are advancing detection systems to identify and mitigate HPEM threats beyond traditional electromagnetic compatibility (EMC) frameworks.

In-House Development of a High-Power Electromagnetics Detector: FORDES from Fraunhofer INT

Fraunhofer INT has spearheaded the development of the Forensic Detection System (FORDES), a groundbreaking HPEM detection system. This system stands out with the following performance characteristics:

• Detects interference frequency as a key parameter of narrowband signals.
• Precisely determines field strength using frequency response compensation while maintaining high measuring dynamics.
• Identifies the incoming direction of signals.
• Captures essential parameters in pulsed disturbances.
• Compact form factor supports versatile use cases with high self-protection.
• Operates on battery power for up to 10 hours, enabling mobile deployment and compensating for power outages.

System Concept and Technical Features

FORDES’s signal processing chain incorporates advanced spiral antennas to capture high-field-strength electromagnetic signals. These signals are attenuated to protect internal electronics, processed, digitized, and temporarily stored. Key parameters such as frequency, pulse width, and pulse number are determined, with further data processing handled by a built-in single-board computer. A web interface facilitates system control and data visualization, while optical interfaces connect the system to a network.

Positioned near sensitive systems like data centers or control rooms, the detection unit provides comprehensive threat monitoring. Well-protected, it logs events locally for forensic analysis, with visual assessments conducted from safer remote locations.

Technical highlights include:

• Recognizing HPEM threats at frequencies up to 10 GHz and field strengths exceeding 10 kV/m.
• Measuring field strengths from 100 V/m up to several kV/m in the 500 MHz to 8 GHz frequency range.
• Shielding against even higher field strengths.
• Compact cubic housing with 19 cm edge length.

Fraunhofer INT’s iterative development approach ensures FORDES’s adaptability to evolving use cases, marking it as a critical component in protection schemes against electromagnetic disturbances.

Conclusion

The techniques of jamming and spoofing represent the forefront of electromagnetic warfare. As nations invest in high-power electromagnetic and intentional electromagnetic interference systems, the stakes in controlling the electromagnetic spectrum have never been higher. These advancements highlight the importance of proactive measures to protect critical infrastructure and military assets in a rapidly evolving technological battlefield.

Glossary from the Fraunhofer Institute:

• EMC is the acronym used for “Electromagnetic Compatibility”. This is the discipline in engineering sciences investigating to what extent electronic devices and systems can disturb neighbouring devices by their own transmissions or be disturbed by them in turn. Before products can be entering the market, their compliance with specific test standards needs to be verified.
• HPEM stands for “High Power Electromagnetics” and designates as an umbrella term phenomenon connected to the generation of intense electromagnetic radiation patterns or conducted voltages and currents. If these do occur, electronic systems can be disturbed or damaged. The strength of interference would usually exceed by far (electric field strength > 100 V/m) the stress conditions electronic devices are submitted to during qualification tests for electromagnetic compatibility (EMC). 
• HPM is a shorthand for “High Power Microwaves”, representing a sub-category of HPEM that has specifically been in use in the past for designating (pulsed) narrowband signals with field strengths beyond 100 (500) V/m or radiated power levels larger than 10 MW.
• IEMI abbreviates “Intentional Electromagnetic Interference”, designating the intentional use of electromagnetic radiation or signals meant to disturb or damage electronic systems for terroristic or criminal purposes.

Further Sources: Fraunhofer Institute, Junge Freiheit