Mobile Antenna System Flashcards
(40 cards)
The radio spectrum is the part of the electromagnetic spectrum with frequencies extending from around ____
1) 3 kHz to 300 GHz
2) 3 MHz to 300 GHz
3) 3 kHz to 300 THz
4) 3 MHz to 300 THz
3 kHz to 300 GHz
_______ defines the aperture of an antenna
1) maximum power beam width
2) half power beam width
half power beam width
At higher frequencies the gain is
often defined with reference to____
1) 3-dB point
1) isotropic radiator
isotropic radiator
has an Omni directional radiation
characteristic in the E-plane and H-plane
The ratio of the power flux density produced by the antenna to that produced by an isotropic radiator at the same distance
1) ERIP
2) VSWR
3) EIRP
Effective isotropic radiated power or
Effective Radiated Power (ERP and EIRP)
The impedance of the antenna is
1) 50 Ohm
2) 100 Ohm
3) 120 Ohm
50 Ohm
Input impedance of the antenna and transmission impedance of the feeder cable should be equal
___ is basically a measure of input impedance mismatch between the transmitter and the antenna
1) ERIP
2) VSWR
3) EIRP
VSWR Voltage Standing Wave Ratio
The higher the VSWR, the ________ is the mismatch
1) greater
2) lesser
greater
The minimum VSWR is ___, which corresponds to a perfect match
1) 100
2) 1
3) 0
1; VSWR = Vmax/ Vmin
A doubling of the number of dipoles results in a gain increase
of ___ dB
1) 2 dB
2) 3 dB
3 dB
radiated power in the horizontal plane is increased if half power beam width is ______
1) increased
2) decreased
decreased
The beam width of Parabolic Reflector antennas depends on the diameter of the antenna and frequency of operation
1) diameter of antenna
2) frequency of operation
3) both
4) none
both
grid types are employed up to __GHz whereas the solid parabolic reflector
antennas are used for higher frequencies.
1) 1GHz
2) 2GHz
3) 3GHz
4) 5GHz
2GHz
which parabolic antenna is used for higher frequencies
1) Solid type
2) Grid type
Solid type.
grid types are employed up to 2GHz whereas the solid parabolic reflector
antennas are used for higher frequencies.
_________ antennas are associated with Satellite communication
1) Grid parabolic
2) Solid Parabolic
3) Cassegrain
4) Array
Cassegrain antennas
_________ antennas are associated with broadcasting and mobile communications
1) Grid parabolic
2) Solid Parabolic
3) Cassegrain
4) Array
Array antennas
The gain and bandwidth of ______ are electrically coupled
1) Cassegrain antennas
2) Yagi antennas
3) logarithmic periodic (log-per) antennas
4) All the above
Yagi antennas
Ideally for field strength the minima of one antenna will be completely compensated by the maxima of the other in
1) polarization diversity
2) space diversity
3) frequency diversity
space diversity
Types of array antennas
1) End Fire Arrays
2) Cassegrain antennas
3) Panel Antennas
4) All the above
(i)End Fire Arrays, (ii) Panel Antennas
Yagi antennas are
1) End Fire Arrays
2) Cassegrain antennas
3) Panel Antennas
End Fire Arrays
logarithmic periodic (log-per) antennas are
1) End Fire Arrays
2) Cassegrain antennas
3) Panel Antennas
End Fire Arrays
Panel antennas are
1) End Fire Arrays
2) Broad side Arrays
Broad side Arrays
_______ uses 2 orthogonally polarized
antennas
1) polarization diversity
2) space diversity
3) frequency diversity
Polarization diversity
_______ uses 2 vertically polarized
antennas
1) polarization diversity
2) space diversity
3) frequency diversity
space diversity
Choose correct item(s)
1) only a minimum spatial separation is necessary for differently polarized dipoles
2) differently polarized dipoles can be mounted in a common housing in same mast
3) dimensions of a dual-polarized antenna are greater than that of a normal polarized antenna
4) all the above
1 and 2
3 is incorrect. dimensions of
a dual-polarized antenna are not greater than that of a normal polarized antenna
