The negative conductance is considered here as a circuit element in the input circuit of the first amplifier stage. It is shown that the lowest value of the noise figure is obtained when the negative conductance is transformed to an infinitely large value. Since this is clearly impossible an ...
The article discusses what the noise figure of an amplifier really means, and uses the example of a chain of two high-gain amplifiers. It turns out that an important ingredient of the definition of the noise figure is often overlooked.
A (hypothetical) noiseless amplifier would have a noise factor of 1, corresponding to a noise figure of 0 dB. Any additional noise may be called excess noise.For an amplifier consisting of two amplifier stages, where the noise factor of each one is known, one can calculate the noise factor...
Noise figure of distributed Raman amplifier with different pumping configurations in S-band: A new approach - ScienceDirect AHB A,MHA B - 《Alexandria Engineering Journal》 被引量: 0发表: 2020年 GaAs microwave power FET A design consideration for an X-band GaAs power FET, features of the ...
The reduction in the noise figure along with a concomitant increase in Raman gain from 2 to 8 dB suggests that lifetimes on the order of 0.1 ns or less are needed to create a useful silicon Raman amplifier that operates in the continuous-wave mode. It is also shown that in devices that...
10.11.1 Definition of noise factor (noise figure) The noise factor, usually of an amplifier, is defined as the ratio of the signal to noise ratio at the input to the signal to noise ratio at the output of the amplifier stage. It indicates the “noisiness” of the amplifier, as in Equ...
Noise figure should be thought of as separate from gain. Once noise is added to the signal, subsequent gain amplifies signal and noise together and does not change the signal-to-noise ratio. Figure 1-2(a) shows an example situation at the input of an amplifier. The depicted signal is 40...
While testing the RTL-SDR for use in this systemthey also measured the noise figureof an R820T RTL-SDR dongle. The noise figure at maximum gain comes out at around 5.6 dB. By adding a low noise amplifier they reduce the measured noise figure down to 2 dB. ...
However, whenever a log-limiting amplifier is used in the signal path (in PM or FM applications), noise figure is clearly important, since it provides a measure of that system's ability to extract information from a signal in the presence of noise. Accordingly, this metric should be ...
Improving Amplifier Noise Figure forHigh 3rd Intercept Amplifiers Wide spurious-free dynamicrange certainly the goal for any IF amplifier. This is particularly true for OTH radar as well as other systems using high resolution digitizers. Recently introduced current feedback amplifiers offer exceptional ...