Mobile Antenna System

Question 1

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

Answer 1

3 kHz to 300 GHz

Question 2

_______ defines the aperture of an antenna
1) maximum power beam width
2) half power beam width

Answer 2

half power beam width

Question 3

At higher frequencies the gain is
often defined with reference to____
1) 3-dB point
1) isotropic radiator

Answer 3

isotropic radiator
has an Omni directional radiation
characteristic in the E-plane and H-plane

Question 4

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

Answer 4

Effective isotropic radiated power or
Effective Radiated Power (ERP and EIRP)

Question 5

The impedance of the antenna is
1) 50 Ohm
2) 100 Ohm
3) 120 Ohm

Answer 5

50 Ohm
Input impedance of the antenna and transmission impedance of the feeder cable should be equal

Question 6

___ is basically a measure of input impedance mismatch between the transmitter and the antenna
1) ERIP
2) VSWR
3) EIRP

Answer 6

VSWR Voltage Standing Wave Ratio

Question 7

The higher the VSWR, the ________ is the mismatch
1) greater
2) lesser

Answer 7

greater

Question 8

The minimum VSWR is ___, which corresponds to a perfect match
1) 100
2) 1
3) 0

Answer 8

1; VSWR = Vmax/ Vmin

Question 9

A doubling of the number of dipoles results in a gain increase
of ___ dB
1) 2 dB
2) 3 dB

Answer 9

3 dB

Question 10

radiated power in the horizontal plane is increased if half power beam width is ______
1) increased
2) decreased

Answer 10

decreased

Question 11

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

Answer 11

both

Question 12

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

Answer 12

2GHz

Question 13

which parabolic antenna is used for higher frequencies
1) Solid type
2) Grid type

Answer 13

Solid type.
grid types are employed up to 2GHz whereas the solid parabolic reflector
antennas are used for higher frequencies.

Question 14

_________ antennas are associated with Satellite communication
1) Grid parabolic
2) Solid Parabolic
3) Cassegrain
4) Array

Answer 14

Cassegrain antennas

Question 15

_________ antennas are associated with broadcasting and mobile communications
1) Grid parabolic
2) Solid Parabolic
3) Cassegrain
4) Array

Answer 15

Array antennas

Question 16

The gain and bandwidth of ______ are electrically coupled
1) Cassegrain antennas
2) Yagi antennas
3) logarithmic periodic (log-per) antennas
4) All the above

Answer 16

Yagi antennas

Question 17

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

Answer 17

space diversity

Question 18

Types of array antennas
1) End Fire Arrays
2) Cassegrain antennas
3) Panel Antennas
4) All the above

Answer 18

(i)End Fire Arrays, (ii) Panel Antennas

Question 19

Yagi antennas are
1) End Fire Arrays
2) Cassegrain antennas
3) Panel Antennas

Answer 19

End Fire Arrays

Question 20

logarithmic periodic (log-per) antennas are
1) End Fire Arrays
2) Cassegrain antennas
3) Panel Antennas

Answer 20

End Fire Arrays

Question 21

Panel antennas are
1) End Fire Arrays
2) Broad side Arrays

Answer 21

Broad side Arrays

Question 22

_______ uses 2 orthogonally polarized
antennas
1) polarization diversity
2) space diversity
3) frequency diversity

Answer 22

Polarization diversity

Question 23

_______ uses 2 vertically polarized
antennas
1) polarization diversity
2) space diversity
3) frequency diversity

Answer 23

space diversity

Question 24

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

Answer 24

1 and 2
3 is incorrect. dimensions of
a dual-polarized antenna are not greater than that of a normal polarized antenna

Question 25

It is also possible to use dipoles at +45°/-45° instead of horizontally and vertically (0°/90°) placed. T/F

Answer 25

T

Question 26

installation personnel should not suffer from _____phobia
1) cleptophobea
2) acrophobia
3) hightophobea

Answer 26

acrophobia

Question 27

Antenna installation specifications
1) Azimuth angle
2) Pitch angle

Answer 27

both

Question 28

Antenna Pitch angle is in the range ____ degree
1) 0 to 10
2) 0 to 30
3) 0 to 45
4) 30 to 45

Answer 28

0 to 10

Question 29

Two antennas of the same sector ____ (must/must not) point to the same direction

Answer 29

must

Question 30

“d” is the horizontal distance between diversity antennas and “H” is the height of the antennas to the ground
1) d≥λ~2λ
2) d≥2λ~4λ
3) d≥10λ~20λ
4) d≥20λ~30λ

Answer 30

d≥10λ~20λ
(or H/d=11)

Question 31

If two antennas of the same sector are
diversity receiving antennas, they should be of the same vertical height (H), and the horizontal distance (d) between them should be _______ possible.
1) as long as
2) as short as

Answer 31

as long as

Question 32

_______ can increase the sensitivity of the base station and increase its range by up to 40%, correcting the link imbalance
1) TMA
2) RET
3) VET

Answer 32

Tower Mounted Amplifier (TMA)

Question 33

TMA stands for
1) Tower Mounted Amplifier
2) Tower Mounted Antenna

Answer 33

Tower Mounted Amplifier

Question 34

VET antenna stands for

Answer 34

Variable Electrical Tilt

Question 35

RET antenna stands for

Answer 35

Remote Electrical Tilt

Question 36

GBTs can accommodate up to __ tenants, RTTs can accommodate ____ tenants
1) 3, 3
2) 6, 3
3) 3, 6
4) 6, 6

Answer 36

6, 2 to 3
GBT: Ground-Based Tower
RFT: Roof-Top Tower

Question 37

It is the ______ of a telecom tower that determines the number of antennas that can be accommodated
1) height
2) strength
3) material

Answer 37

height

Question 38

An azimuth is the direction measured in degrees, clockwise from _______ on an azimuth circle. An Azimuth circle consists of 360 degrees.
1) North
2) East
3) West
4) South

Answer 38

North

Question 39

Azimuth = 270 deg corresponds to
1) North
2) East
3) West
4) South

Answer 39

West
(direction measured in degrees, clockwise from North)

Question 40

outdoor lightning ground wire cross sectional area
1) 10 sqmm
2) 25 sqmm
3) 50 sqmm
4) 100 sqmm

Answer 40

50 sqmm