Which of the following is correct about the power calculation ()? (Select 3 Answers)

In RF power calculations, power in dBm is converted to milliwatts (mW) using the formula $P(\text{dBm}) = 10 \cdot \log{10}(P(\text{mW}))$. Based on this logarithmic scale, 0 dBm corresponds to exactly 1 mW ($10^0 = 1$), making option A correct. An increase of 3 dB doubles the power, so 3 dBm equals approximately 2 mW ($10^{0.3} \approx 2$), making option B correct. Applying standard logarithmic rules ($+10\text{ dB} = \times 10$, $-3\text{ dB} = /2$), 27 dBm can be computed as 30 dBm (1000 mW) minus 3 dB, yielding 500 mW, making option D correct. Option C is mathematically incorrect because 10 dBm equals 10 mW.

C. 10 dBm = 100mW is incorrect because 10 dBm equals 10 mW ($10^{10/10} = 10$); a power level of 100 mW corresponds to 20 dBm ($10^{20/10} = 100$).

1. Huawei Technologies Co., Ltd., HCIA-WLAN V3.0 Training Material, Chapter 2: "RF Fundamentals," Section 2.1: RF Power Units (dBm, mW, dB).

2. ITU-R Recommendation V.574-5, Use of the decibel and the neper in telecommunications, Section 3: Logarithmic units of power.