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2013-03-25 10:17:23


chapter 2 notes
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  1. what is the definition of an antenna
    a transducer that transmit or receives electromagnetic
  2. What frequency ranges do
    cell phone towers in the US operate at?
    • 824MHz –
    • 849MHz, 869MHz – 894MHz, and 1850MHz – 1990MHz.
  3. Most cell site antennas are attached to what type of  platforms?
  4. The
    VHF and UHF bands are used for private and public access services carrying
    speech, data and facsimile information
    • VHF
    • ranges from 30 - 300 MHz,

    UHF ranges from 300 MHz - 3 GHz.
  5. Q. 
    An antenna’s radiation pattern varies depending on what?
    • The antenna configuration, application, and surrounding
    • terrain
  6. What is the Frequency
    range for AM broadcasts? 
    540 kHz through 1600 kHz
  7. .  The majority of VHF television antennas look
    similar to what?
    FM Broadcast Antennas
  8. Q.  What is the definition of an antenna?  
    • .  A device for
    • converting radio waves into an electrical signal or vice versa
  9. The discone antenna
    • is
    • widely used where an omnidirectional wide band or
    • bandwidth RF antenna design is needed
  10. The dipole antenna
    • commonly
    • used types of RF antenna
  11. Stacked Dipole Arrays
    • An
    • array of 2 and 4 centre-fed dipole antennas
  12. Vertical ground plane antennas
    • Consists
    • of a vertical radiator that is mounted directly on the ground and fed at the
    • base
  13. Q.  Which antenna is an
    excellent choice for communications jamming?
    The log periodic antenna
  14. What are the benefits of the Corner Reflector antenna
    It provides high gain and low side lobes
  15. What are the
    frequency ranges of VHF and UHF Antennas?
    VHF ranges from 30MHz – 300MHz  and UHF ranges from 300MHz – 3GHz.
  16. .  Yagi antennas are very widely used as general
    purpose antennas with a gain up to what?
    The Yagi provides gains up to 17 dBi.
  17. cheap and simple to make and operates with freq 12-50 mhz
    yagi antennas
  18. yagi antennas
    gains up to about 17dbi
  19. provides directional capability, excellent for comms jamming
    the log periodic antenna
  20. The
    helical beam antenna
    • wideband
    • impedance characteristics

    circularly polarized radiation

    requires a simple feed network,

    radiation characteristics are reasonably predictable.

    • right-hand or left-hand circular polarization may be
    • generated by a helical beam antenna.
  21. Corner Reflector Antennas
    •Provides high gain and low side lobe levels

    •Below 100 MHz

    •Mechanically cumbersome
  22. Parabolic Antennas
    • •High-gain reflector antenna used for radio,
    • television, data links and communications with satellites.


  23. what are dipoles anntennas?
    most popular omni-directional antennas are simple half wave dipoles