Which unit of measurement is recommended for expressing radio frequency power due to its logarithmic nature?
Correct Answer:
D
Decibel (dB)
Decibel is a logarithmic unit of measure used to express the ratio of two values of the same measure. This unit is not included to the System International of units (SI), but it is widely used in communication systems and many other technical fields, as it allows to compare two values of any nature, provided that these values are expressed in the same unit.
Decibel is a decile of the main, larger unit --- Bel. Bel is a common logarithm of the ratio of two energies. But in practice Bel was a far too big value, therefore its tenth part is used -- decibel.
The logarithmic method of presentation of numbers often can be very useful, as it allows to replace multiplication with addition, division with subtraction, raising to power with multiplication, and extracting a root with the division.
What is measured in dB in the MRFC:
Gain constant
Sound level
Signal/noise ratio
Signal attenuation
https://en.cyclopedia.ifcg.ru/wiki/Radiofrequency_characteristics
