Fundamentals of Radio Waves.txt

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Fundamentals of Radio Waves.txt
2013-03-25 11:53:54
Fundamentals Radio Waves

Fundamentals of Radio Waves
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  1. 1. What are Electromagnetic waves occuring on the radio frequency portion of the spectrum?
    1. Radio Waves.
  2. 2. Radio waves produced by what time of current at high frequencies?
    2. Alternating current (AC).
  3. 3. What is built around a wire when a direct current is applied to a wire?
    3. Electromagnetic Field.
  4. 4. What are the two types of fields?
    4. E-Field (Electronic) and H-Field (Magnetic).
  5. 5. E and H fields that develop in the transfer of energy through space are known collectively as what?
    5. Radiation Field.
  6. 6. This radiation field is responsible for what from any antenna?
    6. Electromagnetic Radiation.
  7. 7. The dynamic structure of E-Fields and H-Fields is known as what?
    7. Electromagnetic Wave.
  8. 8. E-Fields and H-Fields travel at what speed?
    8. Speed of Light.
  9. 9. What is known as the number of waves that pass a fixed place in a given amount of time (1 second)?
    9. Frequency.
  10. 10. What is the highest point on the wave? (Also known as the crest)
    10. Peak.
  11. 11. What is the lowest point on the wave?
    11. Trough.
  12. 12. What is the Amplitude of a sine wave?
    12. Amplitude.
  13. 13. What is measured from the reference line to the peak or the trough?
    13. Peak Amplitude.
  14. 14. What is measured between the maximum positive to negative values?
    14. Peak-to-Peak Amplitude.
  15. 15. What is the completion, from any given point on a wave to the same point on the next wave?
    15. Cycle.
  16. 16. What determine the time it takes for a wave to complete one cycle?
    16. Period.
  17. 17. What is the distance between reapeating units of a wave, usually measured in meters?
    17. Wavelength.
  18. 18. is a moving electromagnetic field that has velocity in the direction of travel and components of electric intensity (E-Field)  and magnetic intensity (H-Field) arranged at right angles to each other?
    18. Radio Wave.
  19. 19. A radiated wave’s polarization is determined by the direction of the _____ __ _____ making up the electric field.
    19. Lines of Force.
  20. 20. If the lines of electric force are perpendicular to the Earth’s surface, the wave is __________ polarized.
    20. Vertically.
  21. 21. If the lines of electric force are parallel to the Earth’s surface, the wave is ____________ polarized.
    21. Horizontally.
  22. 22. What are the two basic linear orientations?
    22. Horizontal and Vertical.
  23. 23. What type of polarization describes a wave whose plane of polarization rotates through 360 degrees as it progresses forward?
    23. Circular polarization.
  24. 24. What type of antennas are used to propagate radio waves in a specific direction while minimizing propagation in others?
    24. Directional Antennas.
  25. 25. What type of antennas are used to propagate radio waves in “all” directions
    25. Omni-Directional.
  26. 26. "The more efficient a certain antenna is for transmitting, the more efficient it
    will be for receiving the same frequency" is known as what?
    26. Reciprocity.