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Converts between power ratios and decibel scale for audio, RF, and other applications. Logarithmic scale matches human perception.
Формула
dBm = 10 × log10(P ÷ 0.001)
- P
- P value — Variable used in the calculation
Пошаговое руководство
- 1dBm = 10 × log10(P ÷ 0.001)
- 2dBW = 10 × log10(P)
- 3Reverse: power (watts) = 10^(dBm ÷ 10) ÷ 1000
- 4Every 3 dB ≈ 2× power
- 5Every 10 dB ≈ 10× power
Решённые примеры
Ввод
Power 1W
Результат
30 dBm
Распространённые ошибки
- ✕Confusing dBm (power) with dBV (voltage) with dBu (relative to 0.775V)
- ✕Adding dBm values instead of multiplying power
Часто задаваемые вопросы
Why use decibels instead of watts?
Logarithmic scale compresses large ranges (1W to 1MW becomes 30 dBm to 60 dBm), easier comparison.
What's typical dBm for audio and RF?
Audio -20 to +4 dBu typical; WiFi transmit +17 to +30 dBm; cellular -30 to +33 dBm.
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