thermal noise

electronics

Also known as: Johnson noise, Nyquist noise

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July 14, 2026

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Thermal noise, also known as Johnson noise or Nyquist noise, is a type of electrical noise that occurs in electronic circuits due to the thermal agitation of free electrons. This random movement of electrons generates a small, unpredictable voltage that can interfere with signals, particularly in radio receivers and amplifiers.12

Physicist Harry Nyquist provided a mathematical explanation for this phenomenon in 1927, building on the work of J.B. Johnson. Understanding and mitigating thermal noise is crucial for the effective functioning of telecommunications systems.2

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Harry Nyquist
…explanation of the unexpectedly strong thermal noise studied by J.B. Johnson. The understanding of noise is of critical importance for communications systems. Thermal noise is sometimes called Johnson noise or Nyquist noise because of their pioneering work in this field.
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…explanation of the unexpectedly strong thermal noise studied by J.B. Johnson. The understanding of noise is of critical importance for communications systems. Thermal noise is sometimes called Johnson noise or Nyquist noise because of their pioneering work in this field.
Read More