In just a very short space of time we’ve gone from using the internet and other devices in a completely hardwired fashion, to everything being wireless. Phones, tablets, watches, laptops, speakers, keyboards, printers, mice, washing machines, and even toothbrushes are all able to be run on various frequency bands, made available through Australia’s mobile phone network infrastructure.
Electromagnetic radiation (EMR) is a phenomenon where energy travels through space in the form of waves, exhibiting both electric and magnetic properties, radiating outward from their source. These waves vary in frequency and wavelength, forming a spectrum that includes familiar elements like radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Mobile phones utilise radio waves, microwaves, and now millimeter waves (mmWaves) which are part of the electromagnetic spectrum, to communicate. When you make a call, send a text, or use mobile data, your phone converts your voice or data into electrical signals. These signals are then transmitted as electromagnetic waves to the nearest cell tower, which relays them through a network of towers and cables to the recipient’s phone.
The recipient’s phone receives these electromagnetic waves and converts them back into sound or data, enabling real-time communication. This seamless exchange of information is made possible by the properties of electromagnetic radiation, allowing phones to send and receive signals over long, or short distances.
The electromagnetic spectrum is the entire range of all electromagnetic radiation (EMR) that exists on Earth, encompassing both natural and non-natural sources (nn-EMR).
The spectrum is divided into bands, ranging from low to high frequency, and includes categories such as radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Each band consists of electromagnetic waves (EM waves) with unique characteristics. Other than visible light, EM waves are invisible waves that are generated by the interaction of oscillating electric and magnetic fields. These waves occur naturally (e.g., sunlight) or can be produced by antennas, circuits, and other man-made technologies.
These waves propagate through space and carry electromagnetic energy. This energy can interact with matter to produce heat, cause chemical reactions, or stimulate biological processes. Man-made EM waves, on the other hand, can be engineered to transmit information, create images, and power modern technologies.
For instance, radio waves are low-frequency, have low photon (light) energy, and long wavelengths. This makes them ideal for uses such as AM and FM radio, where audio signals can be broadcast to receivers over vast distances.
As the waves shorten in wavelength and increase in frequency, they have higher photon energy. At their highest frequencies, EM waves can ionise atoms, breaking chemical bonds. For example, X-rays, which are high-frequency waves, can penetrate through tissues and create diagnostic images of bones and internal structures.