• Intro
    • Electromagnetic Energy = Radio Spectrum
    • The radio spectrum is a naturally occurring resource
  • Radio Basics
    • Electromagnetic Pioneers
      • Jean-Baptiste Fourier (1768-1830) – first theorized an idea of the radio spectrum
      • Guglielmo Marconi (1874-1937) – credited with first successful experiments in wireless telegraphy in the late 19th century
    • there is a system for dividing radio spectrum into discrete bands of frequencies and then allocating those frequencies for different purposes.
      • different portions of the spectrum are suitable for different purposes
    • Electromagnetic Energy
      • different types of waves
        • Sound Waves = Compressional Waves
          • cannot travel in a vacuum
          • move much slower and require a physical medium
        • Radio Waves = Transverse Waves
          • can travel in a vacuum
          • are the result of a ‘vibrating’ magnetic field that is created by a pulsating electrical signal
          • visible light, electricity, and radio waves are all part of the same extended family of energy
          • compared with sound energy, radio waves travel at an extremely high velocity – at the speed of light (about 300,000,000 meters per second)
      • The process of conversion from one type of energy into another and back again is known as modulation and demodulation
        • In many cases radio technologies use both compressional and transverse waves to support human communication (by converting compressional to traverse and then back to compressional).
        • modem = modulation-demodulation
    • Frequency and Wavelength
      • frequency of the signal – the number of energy vibrations reaching an antenna each second
        • one vibration per second is a Hertz (Hz)
          • named after Heinrich Rudolf Hertz (1847-94) – a german physicist who is credited with being the very first person to send and receive radio waves in the laboratory
      • The longer the wavelength, the lower the frequency. The shorter the wavelength, the higher the frequency.