Electromagnetic Waves and Communication Technologies

Electromagnetic Waves

Electromagnetic waves are electromagnetic field disturbances generated by moving charges in the presence of a magnetic field. The electromagnetic material does not need a medium to propagate. Its speed is nearly 300,000 km/s.

Examples of Wave Applications

Common examples include the waves used for television and radio, mobile phones, or satellite links.

The Electromagnetic Spectrum

All sorts of electromagnetic waves are categorized within the electromagnetic spectrum. This includes visible light emission with a wavelength between 700 and 380 nanometers.

Spectrum Regions

• AM Radio
• Television
• Radar
• Infrared
• Visible Light
• Ultraviolet (UV)
• X-rays
• Gamma rays

Properties of Sound

• Intensity: This is proportional to the amplitude of the wave. Strength is measured in decibels and categorized as strong, medium, or slight.
• Tone: The frequency is related to the wave. It can be described as serious or severe.
• Timbre: This is the product of the superposition of the wavelets with the fundamental wave. It can be simple or complex.
• Duration: This is the same magnitude of the wave and can be short or long.

Wireless Transmission

Wireless transmission uses radio waves to transmit data through space. To facilitate the transmission and reception of radio waves, antennas are used. Because electromagnetic waves lose strength with distance, a system of antennas is used that communicates via repeaters. The combined system of antennas and satellites can transmit the same signal between two points on the globe.

Wired Transmission

Wired transmission involves the use of hardware and is required when high quality of transmission is necessary, or when terrain relief and extreme atmospheric conditions make wave propagation difficult.

Types of Cables

• Conventional: This is a copper wire protected by an insulating cover, commonly used for fixed telephony.
• Coaxial: This consists of a central insulated electrical conductor surrounded by a mesh conductor; it is typically used for television antennas.
• Fiber Optic: This consists of a thin thread of glass fiber capable of transmitting light.

Wired and Wireless Comparison

In theory and practice, the choice between these methods depends on efficiency.

• Wired Advantages: Stability and high quality.
• Wired Disadvantages: Increased installation costs.
• Wireless Advantages: Easy spreading and mobility.
• Wireless Inconveniences: Less power and stability.