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

High voltage distribution system or hvds, High Voltage Distribution System ...

High Voltage Distribution System or HVDS Adoption of HVDS (High Voltage Distribution System) through converting existing LVDS to HVDS reduces the technical losses appreciably.

Calculate the maximum power that transmitted to the load, Calculate the Max...

Calculate the Maximum Power That Transmitted To the Load? A 25 MW load at the 33 kV receiving-end busbar of a short 3-phase transmission line has a power factor of 0.8 lagging.

Determine the current and voltage in given network, Q. For a part of the ne...

Q. For a part of the network shown in Figure, given that i 1 = 4A; i 3 (t) = 5e -t , and i 4 (t) = 10 cos 2t, find v 1 , v 2 , v 3 , v 4 , i 2 , and i 5 .

Ac netwoks, hello look for someone that could do i lab report form me on ac...

hello look for someone that could do i lab report form me on ac network, the report is due tonight at 12:00 so only have 8 hours left wondering if anyone is interested in do it? ca

What do you mean by superposition and linearity, Q. What do you mean by Sup...

Q. What do you mean by Superposition and linearity? Mathematically a function is said to be linear if it satisfies two properties: homogeneity (proportionality or scaling) and

What do you mean by conductors and insulators, Q. What do you mean by Condu...

Q. What do you mean by Conductors and Insulators? In order to put charge in motion so that it becomes an electric current, one must provide a path through which it can flow eas

Multiplexing 64-to-1 by using four 16-to-1 multiplexers, Q. Show an arrange...

Q. Show an arrangement for multiplexing 64-to-1 by using four 16-to-1 multiplexers and one 4-to-1 multiplexer.

Define smoothing the output, Define Smoothing the Output? The output of...

Define Smoothing the Output? The output of a DAC is stepped, such as the analog waveforms which were sampled and held. This stepped, or staircase effect is a distortion, and it

Bronze is an alloy of which metal, Bronze is an alloy of  (A) Copper....

Bronze is an alloy of  (A) Copper.  (B)  Aluminium. (C)  Silver.  (D)  Carbon. Ans: Bronze is an alloy of copper.

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