This calculator converts power expressed in dBm (decibels milliwatts) into dBmV (decibels millivolts). This conversion is commonly used to relate power and voltage measurements in RF and CATV systems.
It is useful to radio engineers, cable technicians and RF circuit designers who need to compare power and voltage levels in their designs and measurements.
Formula
dBmV = dBm + 30 + 20 × log₁₀(√Z₀)
Explanation of the formula
- dBm is the input power in decibels milliwatts.
- Z₀ is the characteristic impedance of the system, often 50 Ω or 75 Ω.
- The square root of Z₀ converts the power into equivalent voltage before reporting it in millivolt decibels.
Converting 0 dBm to dBmV for 75 ohms
Input : Power = 0 dBm, Z₀ = 75 Ω
Output : dBmV ≈ 48.75 dBmV
Benefits and uses
- Quickly converts RF powers to equivalent voltages.
- Essential for CATV systems and RF laboratory measurements.
- Facilitates comparison between different electrical units.
- Practical for calibrating and verifying measuring instruments.