The Minimum Detectable Signal (MDS) Calculator estimates the smallest signal power level that a receiver can detect above the noise floor. MDS defines the sensitivity of a receiver system and depends on the noise figure, system temperature, and bandwidth.
Formula
MDS = 10 * log10( (k * T) / (1mW) ) + NF + 10 * log10(BW)
Constants & Units
- k = Boltzmann constant = −228.6 dBW/(K·Hz)
- T = Temperature in Kelvin (default = 290 K)
- NF = Receiver noise figure (dB)
- BW = Receiver bandwidth (Hz, MHz, or GHz)
- MDS result = dBm
Explanation
- MDS represents the minimum power level required for a receiver to distinguish a signal from noise.
- It is also referred to as the “receiver sensitivity.”
- Smaller (more negative) MDS indicates a more sensitive receiver.
Example
Input:
- NF = 5 dB
- T = 290 K
- BW = 1 MHz
Step-by-step:
MDS = −228.6 + 5 + 10 * log10(1,000,000) MDS = −228.6 + 5 + 60 MDS = −163.6 dBm
Output:
- Minimum Detectable Signal (MDS) = −163.6 dBm
Use Cases
- Evaluate receiver performance and noise floor.
- Compare sensitivity between different RF receivers.
- Optimize system design for weak-signal environments.