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what is the definition of an antenna
a transducer that transmit or receives electromagnetic
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What frequency ranges do
cell phone towers in the US operate at?
- 824MHz –
- 849MHz, 869MHz – 894MHz, and 1850MHz – 1990MHz.
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Most cell site antennas are attached to what type of platforms?
triangular
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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.
-
Q.
An antenna’s radiation pattern varies depending on what?
- The antenna configuration, application, and surrounding
- terrain
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What is the Frequency
range for AM broadcasts?
540 kHz through 1600 kHz
-
. The majority of VHF television antennas look
similar to what?
FM Broadcast Antennas
-
Q. What is the definition of an antenna?
- . A device for
- converting radio waves into an electrical signal or vice versa
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The discone antenna
- is
- widely used where an omnidirectional wide band or
- bandwidth RF antenna design is needed
-
The dipole antenna
- commonly
- used types of RF antenna
-
Stacked Dipole Arrays
- An
- array of 2 and 4 centre-fed dipole antennas
-
Vertical ground plane antennas
- Consists
- of a vertical radiator that is mounted directly on the ground and fed at the
- base
-
Q. Which antenna is an
excellent choice for communications jamming?
The log periodic antenna
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What are the benefits of the Corner Reflector antenna
It provides high gain and low side lobes
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What are the
frequency ranges of VHF and UHF Antennas?
VHF ranges from 30MHz – 300MHz and UHF ranges from 300MHz – 3GHz.
-
. Yagi antennas are very widely used as general
purpose antennas with a gain up to what?
The Yagi provides gains up to 17 dBi.
-
cheap and simple to make and operates with freq 12-50 mhz
yagi antennas
-
yagi antennas
gains up to about 17dbi
-
provides directional capability, excellent for comms jamming
the log periodic antenna
-
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.
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Corner Reflector Antennas
•Provides high gain and low side lobe levels
•Below 100 MHz
•Mechanically cumbersome
-
Parabolic Antennas
- •High-gain reflector antenna used for radio,
- television, data links and communications with satellites.
–Off-center
–Cassegrain
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what are dipoles anntennas?
most popular omni-directional antennas are simple half wave dipoles
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