Minimum Detectable Signal Calculator

dB

This calculator finds the Minimum Detectable Signal (MDS), also known as the receiver noise floor. It helps determine the weakest signal level a receiver can detect above the noise level, based on noise figure, temperature, and bandwidth.

Formula

MDS = 10 * log10((k * T) / (1mW)) + NF + 10 * log10(BW)

Formula Explanation

  • k = −228.6 dBW/(K·Hz) (Boltzmann constant)
  • T = Temperature in Kelvin (usually 290 K)
  • NF = Receiver Noise Figure in dB
  • BW = Bandwidth in Hz, MHz, or GHz

Example

Input: NF = 5 dB, T = 290 K, BW = 1 MHz

Result: MDS ≈ −129 dBm

Who uses it

Useful for RF designers and communication engineers evaluating receiver sensitivity in wireless, radar, or satellite systems.