This calculator estimates the thermal noise power (Pn) in dBm generated by an electronic system as a function of temperature and bandwidth. It is essential for assessing the minimum noise level in RF receivers, amplifiers and other sensitive devices.
Formula
Pn = 10 × log10( (k × B × T) / (1 mW) )
Explanation of the formula
Boltzmann’s constant (k = 1.38064852 × 10 -23 J/K) expresses the relationship between thermal energy and temperature. B is the bandwidth in hertz, and T is the absolute temperature in kelvin. The result gives the average thermal noise power in dBm, which increases with temperature and system bandwidth.
Uses of the calculator
- Evaluation of background noise in RF communication systems.
- Performance analysis of low noise amplifiers (LNA).
- Sizing of receivers and filters to minimize losses due to noise.
- Teaching and design tool for engineers and electronics students.