COMMS - Noise

Question 1

is an electronic signal that gets added to a radio or information signal as it is transmitted from one place to another.

Answer 1

Noise

Question 2

It is not the same as interference from other information signals.

Answer 2

Noise

Question 3

is present regardless of whether there is a
signal or not.

Answer 3

Uncorrelated noise

Question 4

exist only when a signal is present (ex. Harmonic
and intermodulation distortion)

Answer 4

Correlated noise

Question 5

is noise that is generated outside the device or circuit.

Answer 5

External Noise

Question 6

is naturally occurring electrical disturbances that originate within Earth’s atmosphere.

Answer 6

Atmospheric noise

Question 7

consists of electrical signals that originate from outside Earth’s atmosphere and is therefore sometimes called deep-space noise.

Answer 7

Extraterrestrial noise

Question 8

is simply noise that is produced by mankind. Sometimes called industrial noise.

Answer 8

Man-made noise

Question 9

is generated directly from the sun’s heat.

Answer 9

Solar noise

Question 10

noise generated by stars outside our solar system.
Often called black-body noise.

Answer 10

Cosmic noise

Question 11

is electrical interference generated within a device or circuit.

Answer 11

Internal Noise

Question 12

is caused by random arrival of carriers (holes and electrons) at the output element of an electronic device such as diode, field effect transistor, or bipolar transistor.

Answer 12

Shot noise

Question 13

noise generated by the time taken by an electron to travel from emitter to the collector of a transistor that becomes significant to the period of signal being amplified.

Answer 13

Transit-time noise

Question 14

random noise generated in a resistance or the resistive component due to rapid and random motion of the molecules (atoms and electrons) inside the component itself.

Answer 14

Thermal noise

Question 15

Also called white noise, Johnson noise and Brownian Noise.

Answer 15

Thermal noise

Question 16

occurs when unwanted harmonics of a signal are produced through nonlinear amplification (nonlinear mixing)

Answer 16

Harmonic Distortion

Question 17

also called amplitude distortion

Answer 17

Harmonic Distortion

Question 18

integer multiples of the original signal

Answer 18

Harmonics

Question 19

combined RMS amplitude of the higher harmonics to the RMS amplitude of the fundamental frequency

Answer 19

Total Harmonic Distortion (THD)

Question 20

is the generation of unwanted sum and difference frequencies produced when two or more signals mix in a nonlinear device.

Answer 20

Intermodulation Distortion

Question 21

is a relative measure of the desired signal power to the noise power.

Answer 21

Signal to Noise Ratio

Question 22

The sum and difference of frequencies

Answer 22

Cross products

Question 23

is the ratio of the S/N power at the input to the S/N power at the output. The device under consideration can be the entire receiver or a single amplifier stage.

Answer 23

Noise Factor or Noise Ratio (f)

Question 24

another way to express the noise in an amplifier or receiver

Answer 24

Noise Temperature

Question 25

means amplification. It is the ratio of a circuit’s output to its input.

Answer 25

Gain

Question 26

An amplifier is _______ when two or more stages are connected together.

Answer 26

cascaded

Question 27

The _______ is the product of the individual circuit gains.

Answer 27

overall gain

Question 28

refers to a loss introduced by a circuit or component. If the output signal is lower in amplitude than the input, the circuit has loss or attenuation.

Answer 28

Attenuation

Question 29

is a unit of measure used to express the gain or loss of a circuit.

Answer 29

decibel (dB)

Question 30

is the number obtained when the base is raised to the logarithm which is the exponent.

Answer 30

antilog