Introduction: What is electromagnetic interference?. Electromagnetic interference (EMI) is undesirable racket or interference in an electrical way or circuit compelled by an external source. This is also known as radio frequency interference.
EMI can cause electronics to malfunction, malfunction, or stop working altogether. EMI can be from natural or manufactured sources. High-quality electronics, electrical shielding, and advanced error correction can reduce the effects of EMI.
A typical example of EMI is when a cell phone is placed near powered audio equipment or speakers, and this causes a series of noises or beeps to be heard. Electromagnetic Interference (EMI) is a prevalent phenomenon in today’s technologically advanced world.
This complex interaction of electromagnetic fields has far-reaching implications across various industries, from telecommunications to medical devices and even everyday electronic devices.
Electromagnetic interference occurs when the electromagnetic fields generated by one electronic or electrical device interfere with the proper operation of another device. This interference can disrupt signal transmission, compromise device functionality, and lead to various issues that affect performance, safety, and reliability.
What is electromagnetic interference?
Understanding EMI requires a grasp of fundamental electromagnetic principles. Electromagnetic fields are formed of electric and magnetic components that oscillate in waves, propagating through space. Devices that generate these fields emit electromagnetic radiation, encompassing various frequencies.
However, these frequencies are sometimes confined to the device’s intended communication spectrum. When these emissions interact with other devices, they can produce undesired effects.
Two main categories define EMI: conducted and radiated interference.
Conducted interference
Conducted interference occurs when electromagnetic noise spreads through electrical conductors, such as power lines or cables, and enters sensitive electronic circuits.
Radiated interference
Radiated interference involves the propagation of electromagnetic waves through the air, affecting devices at a distance.
These types of interference can be further classified into continuous wave (CW) and transient disturbances. CW interference comprises continuous signals, while temporary disorders consist of abrupt, short-duration signals, often originating from lightning strikes or power surges.
What causes electromagnetic interference?
The close relationship between electricity and magnetism causes EMI. All electric current produces a small magnetic field. Conversely, a moving magnetic field has an electric current. These principles permit electric motors and generators to operate.
Additionally, all electrical conductors can act as radio antennas. High-power electrical and radio sources can cause unwanted effects on remote equipment. As electronics become smaller, quicker, more tightly sealed, and more sensitive, they evolve more sensitive to these effects, causing Electro Magnetic interference.
Sources of EMI can be broadly divided into two categories: naturally occurring and man-made. Few sources in the natural world can generate electric fields strong enough to affect electronic devices. Lightning can produce electrostatic solid discharges and magnetic pulses.
Solar storms and flares emit highly charged particles that can cause problems in satellite and terrestrial communications. Cosmic radiation causes bit flips in electronics.
Types of electromagnetic interference
EMI involves a pathway and a receptor (victim). There are 3 modes of transmission of EMI from source to receptor.
- Radiated EMI,
- Conducted EMI, and
- Coupled EMI.
Let’s take a look at each one.
Radiated EMI
Radiated EMI ensues when a high-power transmitter or electrical appliance constructs radio frequencies that are picked up and cause adverse effects in another machine.
If Electromagnetic interference is present, and the source and receptor are far apart, EMI is likely radiated. For instance, an old wireless telephone can block Wi-Fi in the home.
Radiated EMI can be split into two types: narrowband and broadband interference.
- Narrowband EMI affects a specific radio frequency, frequently from radio transmitters.
- Broadband EMI influences a considerable part of the radio spectrum at multiple frequencies and is frequently caused by equipment malfunctions.
Conducted EMI.
Conducted EMI arises when there is a physical, electrical track from the start to the receptor, usually along energy transmission lines. For example, a TV and a washing machine turn on, causing the computer to restart on the same electrical circuit.
Coupled EMI
Coupled EMI occurs when the source and receptor are close to each other but not electrically associated. Coupled EMI can be transmitted by induction or capacitance.
- Inducted or magnetically coupled EMI occurs when a conductor’s magnetic field generates an unwanted current in a nearby conductor. An example of induced EMI is when a power cable and an audio cable are close together, and a hum is heard on the audio line.
- Capacitively coupled EMI occurs when two parallel conductors store a capacitive charge between them. EMI associated with capacitance requires conductors to be close together and is more common on electronic circuit boards or in groups of closely spaced wires running over long distances.
What are the effects of electromagnetic interference?
With the data center, most sources of EMI remain hidden. Uncontrolled EMFs can adversely affect all hardware within a data center, including servers and cables; They also increase the risk of EMF attacks.
Impact on data centers/hardware
When close to strong EMFs, data center cables are exposed to unwanted currents and can experience voltage surges. This creates an electrical “noise” that affects the applications the cables are developed to support.
EMI also induces remote receivers to fail to detect data packets, resulting in packet retransmissions and, in turn, network congestion.
Low-frequency EMI can seriously degrade the performance of data center hardware, even wholly erasing all data on hard disks or solid-state drives (SSDs).
EMF attacks
Hackers can use EMI to enter a data center without physically entering it.
This can lead to:
- The theft of information from databases maintained by servers housed in these centers is done by tapping terminals such as telecommunications equipment that emit weak electromagnetic signals.
- It is exposed to high-power electromagnetic waves directly attacking the data center.
- Producing a crash by exposing a core to a high-power electromagnetic field.
Conclusion
In conclusion, electromagnetic interference (EMI) is a pervasive phenomenon resulting from the interaction of electromagnetic fields emitted by various electronic devices. Its potential to disrupt communication, compromise safety, and degrade performance underscores the importance of addressing EMI during the design and implementation of electronic systems.
By adhering to rigorous design practices, utilizing effective shielding techniques, and complying with regulatory standards, engineers can minimize the impact of EMI and ensure the proper functionality of devices in our increasingly interconnected world.
Also read; Electromagnetic interference and data center, servers and hardware in general; History of Cloud computing; How can I reduce my carbon footprint?
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