Deck 4: Microwave Communication and Modulation

Question 1

The polarization of plane waves received from satellite is changed by_________      

A)faraday rotation
B)gamma rays
C)helical rotation
D)distance travelled

Answer 1

faraday rotation

Question 2

What is the input impedance to a lossless antenna, at resonance?

A)infinite
B)0
C)resistive
D)capacitive

Answer 2

resistive

Question 3

TDMA stands for_________      

A)time division multiple access
B)time domain multiple access
C)time division mutual access
D)time domain mutual access

Answer 3

time division multiple access

Question 4

Which term is used when signals move from one line to another?

A)path switching
B)space switching
C)line switching
D)cross-point switching

Question 5

PSK stands for Pulse Shift Keying.

Question 6

Which term is used for moving PCM samples from one time slot to another?

A)time switching
B)space switching
C)phase switching
D)frequency switching

Question 7

Power can be coupled into or out of a waveguide with a magnetic field probe.

Question 8

What is the full form of LOS?

A)level of signal
B)line of sight
C)loss of signal
D)level of sight

Question 9

How we can define the satisfactory performance of an analog microwave system?

A)carrier to noise ratio that exceeds a given value
B)carrier to noise ratio that is below a given value
C)an erp value that exceeds a given value
D)an erp value that is below a given value

Question 10

RGB stands for_________      

A)red green brown
B)red green black
C)red gold blue
D)red green blue

Question 11

How many lines are there in an NTSC signal?

A)1024
B)1856
C)625
D)525

Question 12

Luminance refers to_________      

A)contrast
B)diffusion
C)brightness
D)aperture

Question 13

Linear modulation techniques are not bandwidth efficient.

Question 14

Which of the following is not a linear modulation technique?

A)oqpsk
B)?/4 qpsk
C)fsk
D)bpsk

Question 15

In BPSK, the_________      of constant amplitude carrier signal is switched between two values according to the two possible values.

A)amplitude
B)phase
C)frequency
D)angle

Question 16

BPSK uses non-coherent demodulator.

Question 17

DPSK uses coherent form of PSK.

Question 18

In DPSK system, input signal is differentially encoded and then modulated using a_________      modulator.

A)amplitude
B)frequency
C)bpsk
D)qpsk

Question 19

QPSK has_________      the bandwidth efficiency of BPSK.

A)twice
B)same
C)half
D)four times

Question 20

QPSK provides twice the bandwidth efficiency and_________    energy efficiency as compared to BPSK.

A)twice
B)half
C)same
D)four times

Question 21

What is the full form of OQPSK?

A)optical quadrature phase shift keying
B)orthogonal quadrature pulse shift keying
C)orthogonal quadrature phase shift keying
D)offset quadrature phase shift keying

Question 22

The bandwidth of OQPSK is_________    to QPSK.

A)identical
B)twice
C)half
D)four times

Question 23

QPSK signals perform better than OQPSK in the presence of phase jitter.

Question 24

Which of the following is not a detection technique used for detection of ?/4 QPSK signals?

A)baseband differential detection
B)if differential detection
C)fm discriminator detection
D)envelope detection

Question 25

Which of the following is a combined linear and constant envelope technique?

A)mpsk
B)psk
C)bpsk
D)qpsk