ARLA/CLUSTER: dB ou não dB..? Eis a questão, no artigo técnico da Rohde & Schwarz.

[João Gonçalves Costa]

Technical Article - dB or not dB?

Everything you ever wanted to know about decibels but were afraid to ask…

True or false: 30 dBm + 30 dBm = 60 dBm? Why does 1% work out to be -40 dB one time but then 0.1 dB or 0.05 dB the next time? 

These questions sometimes leave even experienced engineers scratching their heads. 

Decibels are found everywhere, including power levels, voltages, reflection coefficients, noise figures, field strengths and more. What is a decibel and how should we use it in our calculations? This Application Note is intended as a refresher on the subject of decibels.

The article, downloadable from Rohde & Schwarz, may be of interest to radio amateurs. 

Thanks to the WIA for spotting this very useful guide.

You'll find the download link on the WIA website at:
http://www.wia.org.au/newsevents/news/2011/20110307-2/index.php