What is noise temperature how it is related to noise figure?

The noise figure number, displayed in decibels (dB), represents the performance by which an amplifier or RF receiver can be measured. Noise temperature is a representation of noise in terms of the temperature required to produce an equivalent amount of Johnson-Nyquist Noise.

How does system noise temperature affect the performance?

It shows that the noise temperature of the second stage is divided by the power gain of the first stage when referred to the input. Therefore, in order to keep the overall system noise as low as possible, the first stage (usually as LNA) should have high power gain as well as noise temperature.

What is the meaning of effective noise temperature?

In telecommunications, effective input noise temperature is the source noise temperature in a two-port network or amplifier that will result in the same output noise power, when connected to a noise-free network or amplifier, as that of the actual network or amplifier connected to a noise-free source.

How do you calculate sound temperature?

The noise temperature of rain is usually estimated to be 290 K. Δ T ≅ ( 1 − A r ) × 290 K . For example, if the normal receiver system temperature is 690 K and the rain attenuation is 10 dB (Ar = 0.1), then Δ T = (1 − 0.1) × 290 K = 261 K and the new temperature will be 951 K (a 1.4 dB increase over 690 K).

What is the difference between noise figure and noise factor?

The noise factor is thus the ratio of actual output noise to that which would remain if the device itself did not introduce noise, or the ratio of input SNR to output SNR. The noise figure is simply the noise factor expressed in decibels (dB).

What should be the noise figure value at which the effective noise temperature equal to room temperature?

The ideal value of noise figure is 0 dB.

Why noise temperature is considered as a useful concept in communication receiver?

Noise Temperature gives us another way to describe how much noise a system adds to a signal. In this case, we look at the total noise performance of the system, and calculate an equivalent temperature (Te) that would yield the same noise power at the output via additional thermal noise.

Why is noise temperature a useful concept in communication receivers?

Tt = the “total” noise temperature Another advantage of the use of noise temperature for low noise levels is that it shows a greater variation for any given noise-level change than does the noise figure, so changes are easier to grasp in their true perspective.

What is the equivalent noise temperature for a noise figure of 6dB?

For example, an ambient Noise Figure of 6dB is an ambient Noise Temperature of 1155K.

What is the relation between bandwidth and noise?

The power spectral density of white noise is constant over frequency, which implies that noise power is proportional to bandwidth. So if the measurement bandwidth is doubled, the detected noise power will double (an increase of 3 dB).

What is the ideal and practical values of noise figure?

Typical noise figures for practical receivers are in the range of ~2 to 10dB depending on power, supply voltage, process and circuit design. The sensitivity is the minimum signal level at the receiver input that will meet the CNR of the system, using a receiver of specified noise figure.

What is noise factor in communication?

Noise Factor is the measure of degradation of the signal to noise ratio in a device. It is the ratio of the Signal to Noise Ratio at the input to the Signal to Noise Ratio at the output. The Noise Figure is noise factor expressed in decibels (dB).