Noise Flashcards
Any unwanted form of energy tends to interfere with the proper and easy reception and reproduction of wanted signals.
Noise
Any undesired voltage or current that ultimately ends up appearing in the receiver output.
Noise
Results of Noise
- hissing/static
- snow/confetti
- Echo/ feedback
- bit errors
- signal loss
mutually related to the signal and cannot be present in a circuit unless there is an input signal and is produced by nonlinear amplification. No signal, no noise.
Correlated Noise
Types of Correlated Noise
-Harmonic Distortion
-Intermodulation Distortion
unwanted harmonics of a signal
Harmonic Distortion
the generation of unwanted sum and difference frequencies (cross products) when two or more signals are amplified in a nonlinear device.
Intermodulation Distortion
Present regardless of whether there is a signal present or not.
Uncorrelated Noise
Types of Uncorrelated Noise
External and Internal Noise
generated outside the device or outside the receiver circuit
External Noise
noise directly from the sun’s heat
Solar Noise
naturally occurring electrical disturbances that originate within the Earth’s atmosphere
Atmospheric Noise
consists of electrical signals that originate from outside the earth’s atmosphere.
Extraterrestrial Noise
Noise from the stars
Cosmis Noise
generated within the device or within the receiver circuit.
Internal Noise
produced by manufactured equipment such as automotive ignition systems, electric motors and generators.
Man-made Noise
associated with the rapid and random movement of electrons within a conductor due to thermal agitation
Thermal Noise
a form of internal noise which is due to therandom variations in current flow in activedevices such as tubes, transistors and diodes.
Shot Noise
caused by the random arrival of carriers (holes and electrons) at the output element of an electronic device.
Shot Noise
shows up as a kind of random noise within the device and is directly proportional to the frequency of operation.
Transit-time Noise
