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Why do super-cooled circuits make signals clearer? Uncovering the mystery of cryogenics!
In the world of electronic devices, optimizing signal clarity has always been a critical task for engineers. One of the key points is to use cryogenic technology to reduce noise and thus improve the signal-to-noise ratio. In this article, we’ll explore how ultra-cool circuits work and why signals can be transmitted more clearly in such a clean environment.
So-called Johnson-Nyquist noise is noise generated by the thermal motion of electrons within an electrical conductor, a phenomenon that occurs automatically under any applied voltage.
This type of noise is ubiquitous in all circuits, but is especially so in sensitive electronic equipment such as radio receivers, where the presence of thermal noise can be enough to drown out weak signals. Therefore, to increase the sensitivity of these devices, many sensitive electronic components (such as radio telescope receivers) are cooled to temperatures close to absolute zero to significantly improve the signal-to-noise ratio.
What is thermal noise?
Thermal noise, also known as Johnson noise, is noise generated by the random motion of electrons in an electrical conductor. In an ideal resistor, the characteristics and intensity of this noise are described by the following formula:
Vn² = 4kBTΔfR
Where kB is the Boltzmann constant, T is the absolute temperature, Δf is the bandwidth, and R is the resistance value. This formula shows how thermal noise increases as temperature increases, which is why when the ambient temperature decreases, the thermal noise also decreases, ultimately making the signal clearer.
Cooled electronics can significantly reduce the effects of thermal noise, making the signal more stable during reception.
How does cryogenics improve signal clarity?
During the low temperature treatment process, the equipment can achieve the following advantages:
Reduced thermal noise: At low temperatures, the thermal motion of electrons is reduced, and the noise associated with it is also reduced, which is particularly important in electronic devices that make high-sensitivity measurements.
Increase signal sensitivity: As noise decreases, signal sensitivity continues to increase, and weaker signals can be received.
Improve signal-to-noise ratio: The improvement of signal-to-noise ratio makes the signal more distinguishable from background noise, thereby improving the overall communication quality.
Application examples of thermal noise at low temperatures
With the increasing application of cryogenic technology, many cutting-edge scientific and technological fields have begun to use this technology to perform high-precision measurements. One notable example is the 2017 measurement of the Boltzmann constant by NIST (National Institute of Standards and Technology) using Johnson noise thermal measurement with an uncertainty of less than 3 ppm, which paved the way for the redefinition of the New foundation.
The core of this research work is to combine voltage measurement with thermal noise technology to achieve high-precision measurement results.
ConclusionIt can be said that cryogenic technology not only has a significant impact on the performance of electronic equipment, but also greatly improves the accuracy of scientific measurements.
The role of cryogenic technology in electronic devices cannot be underestimated. The development of this technology not only improves the performance of communication equipment, but also provides important support for high-precision scientific measurements. As research on cryogenic technology deepens, we can expect more breakthrough applications to emerge in the future. Will this trigger a new technological revolution?
