Electromagnetic Environment in the Modern World

The modern world is surrounded by electromagnetic fields, and it's essential to understand the impact they have on our daily lives. We're constantly exposed to electromagnetic radiation from various sources, including our homes, workplaces, and even our personal devices.

The average person is exposed to around 2.5 volts per meter of electromagnetic field strength in their home, which is relatively low. However, this can increase significantly in areas with high power lines or cell towers.

Electromagnetic fields can affect the human body, particularly the nervous system, and have been linked to health issues such as headaches and fatigue.

The Electromagnetic Environment is a critical aspect of our modern world, and it's essential to understand its complexities. Electromagnetic waves are virtually the only easy and safe way to communicate with a spacecraft, making antennas and propagation two core elements in spacecraft engineering.

Radio waves are used for a wide spectrum of applications, including telecommunication, observation of Earth (or other planets) from a distance, and radio-navigation. Special antennas need to be designed for all these purposes, and the desired or undesired wave propagation effects have to be assessed.

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The natural space environment consists of high energy particle radiation, plasmas, gases, and particulates. Assessing the performance of satellite receivers combined with ground station antennas for telemetry, tracking, and telecommand (TT&C) applications is another core activity.

Radiation from the Earth's radiation belts, from explosive events on the Sun, and from galactic cosmic rays can damage electronic components, detectors, and humans. Plasmas can give rise to high levels of electrostatic charge on a spacecraft's surfaces, leading to electrostatic discharge.

The Electromagnetic Environment is a global area with little regulation, it is vital for the economy, and it is therefore necessary to protect it. The Global Commons, including the Electromagnetic Environment, are where the world trade occurs, and denying their use would result in devastating consequences for the economy of any country.

The Electromagnetic Environment is closely linked to globalization, which demands interconnectivity between the Global Commons to provide high standards of living or societies. The disruption of a Global Common has an impact on the other domains and can have economic, social, and geopolitical consequences.

The Russian Federation's exploitation of the spectrum puts NATO forces at a disadvantage in congested and contested scenarios, highlighting the vulnerabilities of the Global Commons. The Electromagnetic Environment has all the characteristics of being a Global Common, making it essential to protect and guarantee access to it.

The electromagnetic environment has a significant impact on our daily lives. It affects the performance of electronic devices, which can be crucial in emergency situations.

Radio frequency interference (RFI) can cause malfunctions in medical devices, such as pacemakers and implantable cardioverter-defibrillators (ICDs). This can be life-threatening.

Electromagnetic interference (EMI) can also disrupt communication systems, leading to errors and delays in critical applications like air traffic control.

The new nature of conflicts is a complex and challenging landscape for NATO, with the Global Commons playing a central role in the geopolitical arena.

The impact of a Global Common disruption on national economies is potentially catastrophic, making it essential for nations to protect these shared resources.

Exploiting vulnerabilities without escalating the crisis is the strength of hybrid warfare, which has become more readily available, affordable, and easy to exploit, not only for states but also for non-state actors.

Problems arise when actions are taken to prevent persons, organizations, or nations from freely accessing Global Commons, often by exploiting weaknesses in the security structures of western states using evolving technologies such as Electronic Warfare (EW).

In scenarios heavily influenced by adversaries' Electronic Military Operations (EMO), accomplishing a single military action may be difficult since aggressions often occur below NATO's Article 5 threshold.

The opportunity to employ EMO actions may provide added value in modern conflicts, offering the option to respond with non-kinetic actions, such as degrading or disrupting a Global Common.

However, accurate or timely responses are frequently difficult to achieve since attribution can be difficult to prove, making it challenging for NATO to respond effectively.

NATO needs to acknowledge that the EME rules the Global Commons and conceptualize and structure its capabilities towards this notion.

Radiation from the Earth's radiation belts, from explosive events on the Sun, and from galactic cosmic rays can damage electronic components, detectors, and humans. This is a serious concern for spacecraft designers.

High levels of electrostatic charge on a spacecraft's surfaces can lead to electrostatic discharge, which is the space equivalent of a lightning strike. This can be caused by plasmas and is a major risk for spacecraft.

The space environment also includes particulates such as micrometeoroids and small space debris, which can puncture spacecraft and systems, causing damage or serious hazards on manned missions. This is a critical factor in developing spacecraft.

Atmospheres can cause drag and on Mars, for example, can be used to brake spacecraft. This is an important consideration for spacecraft designers.

The natural space environment consists of high energy particle radiation, plasmas, gases, and particulates, which can have a significant impact on space systems. This is a major area of study for spacecraft engineers.

Electromagnetic interference is tipped to become more important with the introduction of next-generation broadband telecom satellites that incorporate multiple spot beams operating at higher frequencies. This is a significant challenge for spacecraft designers.

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Interference is a major issue in signal processing, and it can be caused by various factors such as noise, crosstalk, and multipath effects.

In wireless communication systems, multipath effects can cause significant interference, leading to signal degradation and errors.

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Multipath effects occur when a signal arrives at the receiver via multiple paths, causing the signal to be distorted and weakened.

In some cases, the signal can be completely cancelled out by the destructive interference caused by the multiple paths.

Multipath effects are more pronounced in environments with a lot of reflective surfaces, such as buildings and hills.

In such environments, the signal can bounce off multiple surfaces before reaching the receiver, causing significant interference.

However, some systems, such as OFDM (Orthogonal Frequency Division Multiplexing), are designed to mitigate the effects of multipath interference.

These systems use multiple carriers to transmit the signal, which can be recombined at the receiver to form a single, error-free signal.

This approach can significantly improve the reliability and efficiency of wireless communication systems.

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In an electromagnetic environment, there are various characteristics and types of electromagnetic interference (EMI) to consider.

The TEM Cell, for example, has a working volume with dimensions of 4x11x5 meters. The electric field in this cell can reach a maximum intensity of 250 kV/m at 4 meters.

Types of interference can be categorized based on their source and signal characteristics. Electromagnetic interference can be man-made or natural, and it's often referred to as "noise" in this context.

Continuous wave (CW) interference, which comprises a given range of frequencies, can be further divided into narrowband and broadband categories.

Here's a summary of the frequency ranges and their corresponding electric field intensities:

Performance Characteristics are a crucial aspect of understanding how a device performs under different conditions. The TEM Cell, for example, has a length of 24 m.

The working volume dimensions of the TEM Cell are 4x11x5 m (HxWxL), which is quite spacious. This allows for a variety of experiments to be conducted within the cell.

The electric field polarization of the TEM Cell is vertical, which is a key characteristic to consider when designing experiments. This orientation can impact the way the electric field interacts with the surrounding environment.

In terms of electric field intensity, the TEM Cell can produce a maximum of 125 V/m at 4 m when operating in continuous wave mode at frequencies between 100 KHz and 250 MHz. This is a significant range of frequencies that can be explored.

For pulsed mode, the electric field intensity is even higher, reaching 250 kV/m at 4 m. This is a notable difference from the continuous wave mode, highlighting the importance of considering the mode of operation when designing experiments.

Here's a summary of the electric field intensity for both continuous wave and pulsed modes:

Types of Interference can be categorized into several types according to the source and signal characteristics. Electromagnetic interference, or EMI, is a common issue that can be caused by both man-made and natural sources.

Continuous wave, or CW, interference is a type of interference that comprises a given range of frequencies. This type of interference is naturally divided into sub-categories according to frequency range, and is sometimes referred to as "DC to daylight". For example, the EMES TEM Cell has a CW frequency range of 100 KHz-250 MHz, with a maximum electric field intensity of ≤ 125 V/m at 4 m.

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Electromagnetic pulses, or EMPs, are short-duration pulses of energy that are usually broadband by nature. In the case of the EMES TEM Cell, a pulsed EMP has a maximum electric field intensity of 250 kV/m at 4 m.

Types of interference can be further divided into narrowband and broadband, according to the spread of the frequency range. This classification is useful for understanding the characteristics of different types of interference and how to mitigate their effects.

Design is a crucial aspect of preventing electromagnetic interference (EMI). A design that easily couples energy to the outside world will equally easily couple energy in and will be susceptible.

Grounding and shielding are essential techniques to reduce emissions or divert EMI away from the victim. Techniques include grounding or earthing schemes such as star earthing for audio equipment or ground planes for RF.

Shielded cables are another effective way to reduce EMI, where the signal wires are surrounded by an outer conductive layer that is grounded at one or both ends. Shielded housings can also act as an interference shield, typically made in sections with an RF gasket at the joints to reduce interference.

Decoupling or filtering at critical points such as cable entries and high-speed switches is also important, using RF chokes and/or RC elements. A line filter implements these measures between a device and a line.

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Here are some specific techniques to reduce emissions:

Designing for operation at lower signal levels can also reduce emissions by reducing the energy available for emission.

There are four basic coupling mechanisms that can occur between a source and a victim: conductive, capacitive, magnetic or inductive, and radiative. These mechanisms work together to form the coupling path.

Conductive coupling occurs when there's direct electrical contact between the source and victim through a conducting body. This is often seen in situations where wires or cables are in close proximity.

Capacitive coupling happens when a varying electrical field exists between two adjacent conductors, inducing a change in voltage on the receiving conductor. This can be a problem in electronic devices with multiple components.

Magnetic or inductive coupling occurs when a varying magnetic field exists between two parallel conductors, inducing a change in voltage along the receiving conductor. This is often seen in situations where coils or wires are in close proximity.

Radiative coupling, or electromagnetic coupling, occurs when the source and victim are separated by a large distance and act as radio antennas, emitting and receiving electromagnetic waves.

The control of electromagnetic interference (EMI) is crucial to prevent unacceptable risks in many areas of technology. To control EMI, we need to characterise the threat, set standards for emission and susceptibility levels, design for standards compliance, and test for standards compliance.

Here are the key disciplines involved in controlling EMI:

These disciplines help us reduce the probability of disruptive EMI to an acceptable level, rather than its assured elimination.

Coupling mechanisms are the ways in which interference travels from a source to a victim. There are four basic mechanisms: conductive, capacitive, magnetic or inductive, and radiative.

Conductive coupling is formed by direct electrical contact with a conducting body. This is a common issue in electronic devices.

Capacitive coupling occurs when a varying electrical field exists between two adjacent conductors, inducing a change in voltage on the receiving conductor. This can happen in situations where wires are close together.

Inductive coupling or magnetic coupling occurs when a varying magnetic field exists between two parallel conductors, inducing a change in voltage along the receiving conductor. This is often seen in power lines and electrical systems.

Radiative coupling or electromagnetic coupling occurs when source and victim are separated by a large distance. The source emits an electromagnetic wave that propagates across the space and is picked up by the victim.

Controlling electromagnetic interference (EMI) is crucial to prevent damage to technology. This involves reducing the risks to acceptable levels.

The control of EMI and electromagnetic compatibility (EMC) involves several disciplines, including characterising the threat, setting standards, designing for compliance, and testing for compliance.

To characterise the threat, you need to understand the interference source and signal, the coupling path to the victim, and the nature of the victim, both electrically and in terms of the significance of malfunction.

Additional measures to reduce susceptibility include:

Designing for standards compliance is a key part of controlling EMI. This may involve producing a dedicated EMC control plan, which summarises the application of the above disciplines and specifies additional documents required.

In many cases, reducing the probability of disruptive EMI to an acceptable level is sufficient, rather than its assured elimination.

Testing is a crucial part of ensuring that a system's coupling and control are functioning as intended.

In the context of a complex system, testing involves verifying that the individual components are interacting correctly with each other. This can be a challenging process, especially when dealing with a large number of components.

A good testing strategy involves identifying the critical paths and testing those areas first. This approach helps to isolate issues and prevent them from cascading throughout the system.

For example, in a system with multiple feedback loops, testing each loop individually can help to identify potential problems.

Legislation plays a crucial role in ensuring electromagnetic compatibility. Different nations have their own laws and regulations regarding electromagnetic compatibility.

In the European Union, EU directive 2014/30/EU (previously 2004/108/EC) on EMC defines the rules for the placing on the market/putting into service of electric/electronic equipment within the European Union. This directive applies to a vast range of equipment, including electrical and electronic appliances, systems, and installations.

Manufacturers of electric and electronic devices are advised to run EMC tests to comply with compulsory CE-labeling. Compliance with the applicable harmonised standards whose reference is listed in the OJEU under the EMC Directive gives presumption of conformity with the corresponding essential requirements of the EMC Directive.

In the United States, a program for the protection of critical infrastructure against electromagnetic pulses was adopted in 2019. This program aims to safeguard critical infrastructure against both geomagnetic storms and high-altitude nuclear weapons.

The main national organizations responsible for electromagnetic compatibility are listed below:

In the end, it's essential to understand the impact of the electromagnetic environment on our daily lives.

Radiofrequency radiation from cell towers and Wi-Fi routers is a significant contributor to electromagnetic pollution.

The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has established guidelines for safe exposure limits to electromagnetic fields.

A key aspect of managing electromagnetic pollution is to use shielding materials to block or absorb electromagnetic radiation.

EMI can be mitigated through the use of twisted pair cables and shielded cables in electronic devices.

The FCC regulates the use of electromagnetic radiation in the United States, setting limits for safe exposure.