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# Transformation sinus signal + Gaussian white noise

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#### cerg19

##### Newbie level 2
Hi. I first time write in this forum.
I am lookin for a information about transformation sinus signal + Gaussian white noise passing through diode(or some other nonlinear element). I am interested in output signal noise dispersion. Please, advise book or paper about this.
Regards,
Sergey

There were many books on this problem in 1960s. I studied this problem from a book by Levin, Statistics in Electronics, in Russian

I studied this problem from a book by Levin, Statistics in Electronics, in Russian
This must be the same book that was translated to spanish with the title "Fundamentos De Radiotecnia Estadistica" and published by Marcombo. I don't know if there is an English translation.
If I'm not wrong, the problem is treated also in "An Introduction to the Theory of Random Signals and Noise" by Davenport and Root, a book from the '50 or 60's and edited again by Wiley - IEEE Press in the 80's.
Regards

Z

This must be the same book that was translated to spanish with the title "Fundamentos De Radiotecnia Estadistica" and published by Marcombo. I don't know if there is an English translation.
If I'm not wrong, the problem is treated also in "An Introduction to the Theory of Random Signals and Noise" by Davenport and Root, a book from the '50 or 60's and edited again by Wiley - IEEE Press in the 80's.
Regards

Z

I think you are right! I have tried to study Davenport & Root, too, but Levin's analysis was easier to understand.
In short, detecting a CW signal functions as a rectification, with the "opening angle" concept. At higher input level, harmonics are generated and the detector rather becomes a frequency multiplier.
Diode pairs are in fact used to multiply the input frequency.

Detecting noise is different. The Gaussian noise is converted to Rician and its spectrum varies with the input noise intensity.Detectors are evaluated by the tangential sensitivity using a keyed input noise, and the amplitude response changes from "quadratic" to linear.

The combined input, CW plus noise, is quite complex process. Detector output spectrum becomes a trapezoid in shape, one-sided around zero frequency, and double-sided around CW input harmonics.

Vacuum-diode detectors were common when the mentioned books were written. Later, P/N junction diodes were introduced, and Schottky diodes which all differ by the A/V response exponent.
The newest device is the S-I-S or Josephson junction which only operates deep cooled but offers a multiple-step A/V response, making it a wonderful microwave mixer.

I am not aware if a newer book has been available describing the detector operation in the light of newer devices. Even as I have made and experimented with DC-biased detectors and mixers, I do not know if a good theory exists about them.

thank you for answers, I am from russia and try to find Levin in original

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