Explain about amplifier noise, Electrical Engineering

Assignment Help:

Q. Explain about Amplifier noise?

Amplifier noise arises from both thermal sources (resistances) and nonthermal sources (semiconductor devices). Although nonthermal noise is not related to physical temperature and does not necessarily have a uniform spectrum like that of thermal noise, one still refers to an amplifier's noise temperature Ta, for convenience, as a measure of noisiness referred to the input. The model of a noisy amplifier is shown in Figure (a) with input noise N = ηB = kTB from a source at temperature T, and the output power given by


Nout = GN + Na = GN + GkTaB = Gk(T + Ta)B

where Na = GkTaB is the output noise power caused only by the amplifier, G is the power gain of the amplifier, and B is the bandwidth of the amplifier. Note that the amplifier noise Na is added to the amplified source noise to yield the output power in Equation. If T = T0 (i.e., room temperature), then Nout ≅ Na, and the amplifier noise dominates the source noise, which is a common occurrence. When Ta >> T0, the amplifier is very noisy, although not physically hot.

Figure (b) depicts the variation of noise temperature with frequency for a nonthermal source. Several phenomena lumped together under the term one-over-f (1/f ) noise lead to the pronounced low-frequency rise in Figure (b). Such 1/f noise is produced by transistors and certain transducers, such as photodiodes and optical sensors.

1761_Explain about Amplifier noise.png


Related Discussions:- Explain about amplifier noise

Discuss the operation of the jk flip-flop, Q. Figure shows the master-slave...

Q. Figure shows the master-slave JKFF. Assuming that the output changes on the falling edge of the clock pulse (i.e., when the clock pulse goes from high to low), discuss the opera

What is microprocessor, What is Microprocessor? Give the power supply & clo...

What is Microprocessor? Give the power supply & clock frequency of 8085. A microprocessor is a multipurpose, programmable logic device that reads binary instructions from a sto

MATLAB, Flicker noise: I’d like to plot the graph of the flicker noise foun...

Flicker noise: I’d like to plot the graph of the flicker noise found in the data sheet for the amplifier (will be provided later) and also generate the equation for that graph sho

Advantages and disadvantages of aluminium, Discuss the advantages and disad...

Discuss the advantages and disadvantages of aluminium as compared to copper as a conductor of electricity. Advantages: Aluminium as a conductor of electricity as compared co

Phantom or fictitious loading method, Phantom or Fictitious Loading Method ...

Phantom or Fictitious Loading Method While the capacity of meters under test is extremely high, testing with actual load method would includes a considerable loss of power and

What are the currents in the high-voltage, Q. A transformer is rated 10 kVA...

Q. A transformer is rated 10 kVA, 220:110 V (rms). Consider it an ideal transformer. (a) Compute the turns ratio and the winding current ratings. (b) If a 2-load resistance

Stack operation, Stack Operation Stack is a group of memory  locations...

Stack Operation Stack is a group of memory  locations which  are part of the  same read write memory  used for  storing  data  temporarily  during the execution of the  progra

Types of field-effect transistors, Types of Field-Effect Transistors T...

Types of Field-Effect Transistors The channel of a FET (field-effect transistor) is doped to produce either an N-type semiconductor or a P-type semiconductor. The drain and so

Show voltage wave form of rlc series circuit, Q. The voltage wave form of F...

Q. The voltage wave form of Figure is applied to an RLC series circuit with R = 2, L = 2H, and C = 1 F. Obtain i(t) in the series circuit. (Note that the capacitor and inductor va

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd