Answer:
L (in dB) = 20 log f + 20 log d + 32.44
with f in MHz and d in Km
Explanation:
L(in dB) = 20 log f + 20 log d - 147.56 dB
with f in Hz and D in m
MHz = 10⁶ Hz
And
Km = 10³ m
L(in dB) = 20 log f + 20 log d - 147.56 dB
L = 20 log [10⁶f] + 20 log [10³d] - 147.56
L = 20 log 10⁶ + 20 log f + 20 log 10³ + log d - 147.56
From the law of logarithms,
Log 10⁶ = 6
Log 10³ = 3
L = (20×6) + (20×3) + 20 log f + 20 log d - 147.56
L = 20 log f + 20 log d - 147.56 + 120 + 60
L (in dB) = 20 log f + 20 log d + 32.44
Hope this Helps!!!
