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Characteristics of Radio Frequency (RF)

Physics of light

RF is light waves
wave-particle duality - sometimes light behaves as a wave or particle.
speed of light - c=2.99x1082.99x10^8 m/s

Waveform

Crest - Peak of wave
Trough - bottom of wave
Origin - middle of wave
Amplitude - distance between crest and trough
Period - time that it takes for one cycle of the wave
Phase - distance between the same point on two different waves, complete opposite is 180o
Frequency - number of cycles per seconds - Hertz Hz - Visible light 400THz - 800THz
Wavelength - same as period, but physical distance instead of time (5GHz 6cm, visible 400-700nm)
Wavelength and Frequency are inversely proportional, C = λ x f

Electromagnetic Spectrum

  • Radio Region
  • Microwave Region (Wi-Fi)
  • Infrared Region
  • Visible Region
  • Ultraviolet Region
  • X-Ray Region
  • Gamma Region
Lower the frequency the greater the distance it can travel at the same energy level.
Propagation - passing thorough obstacles

Wireless Measurements

Wireless Transmit Power

Power level drops over distance.
Cell - coverage of an AP
Power (Watt) = Energy over time

Decibel

dB is linear - Logarithm - deci = 1/10
Logarithm - how many times to get number. log3 27 = 3x3x3
Log10 = Log