Deck 4: How Antennas Work

Question 1

To work as efficiently as a dipole, a monopole antenna requires a(n) _______.

A) LMR cable
B) longer length
C) ground plane
D) amplifier

Answer 1

C

Question 2

In a direct, point-to-point link, the Fresnel zone should never be obstructed more than _______.

A) 40 percent
B) 60 percent
C) 30 percent
D) 50 percent

Answer 2

A

Question 3

What happens if someone sets up a pair of antennas that interfere with your point-to-point link between two buildings that uses an unlicensed frequency?
You will have to resolve the issue yourself by raising or lowering the height of your antennas, because the regulatory agencies will not assist you.

Answer 3

You will have to resolve the issue yourself by raising or lowering the height of your antennas, because the regulatory agencies will assist you

Question 4

Passive antennas can be designed in a way that effectively increases the strength of a signal in a particular direction.

Question 5

Between the transmitting antenna and the receiving antenna, a signal will always be subject to _________.

A) gain
B) amplification
C) free space loss
D) reflection
E) diffraction

Question 6

A(n) _________antenna transmits a signal in all directions with relatively equal intensity.

A) multidirectional
B) phased array
C) directional
D) omnidirectional
E) smart

Question 7

The ________ of an antenna depends upon the frequency of the RF signal and the gain.

A) length
B) amplification
C) width
D) height

Question 8

One of the purposes of a(n) ________ is to emit an electromagnetic signal into air or space.

A) antenna
B) modulator
C) filter
D) mixer

Question 9

Decibel is a relative measurement that requires a(n) _________.

A) distance
B) antenna
C) power level
D) comparison
E) gain

Question 10

How do sky waves propagate?
Sky waves bounce between the ionosphere and the surface of the earth.

Question 11

List two types of directional antennas.
Dish, Yagi

Question 12

How do smart antennas function?
They track the location of the mobile receiver and send a narrower beam to prevent wasting energy.

Question 13

A directional antenna typically has a low gain.

Question 14

When planning a wireless link, you should always prepare a ______ to ensure that the signal that reaches the receiver meets the minimum signal strength requirements.

A) free space loss
B) proposal
C) link budget
D) specification

Question 15

A lower frequency signal uses a ________ antenna, whereas a higher frequency signal uses a _______ antenna.

A) shorter, longer
B) longer, shorter
C) higher, lower
D) lower, higher

Question 16

For the best performance between transmitter and receiver, the two antennas should have the same ________.

A) size
B) angle
C) gain
D) polarization

Question 17

The simplest and most practical type of antenna is a _______ antenna.

A) straight wire
B) dipole
C) yagi
D) monopole
E) passive

Question 18

The gain of an antenna is the measure of how ______ the direction of an antenna pattern is.

A) focused
B) wide
C) large
D) low

Question 19

A transmitter generates a 15 dBm signal and is connected to an antenna using a cable that induces a 3 dB loss. The cable has two connectors that induce a loss of 2 dB each. What is the signal level at the input of the antenna?

A) 8 dBm
B) 10 dB
C) 22 dBm
D) 3 db

Question 20

A gain of 6 dB means that the signal level or strength _________.

A) increases very little
B) doubles
C) doubles twice
D) does not increase at all