Short Questions and Answers on Noise Theory

Q.1. Noise from the sun and stars is called ……………….. noise.

Ans. extraterrestial.

Q.2. Thermal noise is also called as …………….

Ans. Johnson noise

Q.3. Write short note on burst noise.

Ans. Burst noise is a type of electronic noise that occurs in semiconductor.

It is also called impulse noise, bistable noise or random telegraph signals (RTS noise).

It consists of sudden step like transistors between 2 or more levels, as high as several hundred millivolts at random and unpredictable times. Each shift in offset voltage or current last for several milliseconds, and interval between pulses tend to be in audio range, leading to the term popcorn noise for the popping or crackling sounds it produces in audio circuits.

Q.4. What do you mean by Avalanche noise

Ans. Avalanche noise is a noise of a reverse biased emitter-base junction of a bipolar silicon transistor is a low frequency spectra.

It appears that 1/f noise is not directly related to the direct current flowing at Avalanche breakdown condition.

In the width of 0.24 mm structure an effective b/a ratio of approximately 0.4 is deduced from the excess noise factor even when electrons initiate multiplication, suggesting that hole initiated multiplication is not always necessary for the lowest avalanche noise in lnP – based Avalanche photodiodes.