Power levels are very important when dealing with communication electronics. Gains and attenuation are likewise used to design antenna type and dimensions for efficient transmission and reception. Usually, power levels are measured in terms of decibels. A decibel is defined as unit of measure between two power levels with the use of logarithms between them.
In the past, decibels were commonly used to measure sound intensities. However, it is very convenient for power levels to be converted to decibel values. This is because values could become unwieldy when dealing with very large or very small values. The equation for calculating the decibel value of two power levels is given by ten times the logarithm of the ratio of the power levels with uniform units. However, simple decibel value can be confusing in problems that involve multiple power levels and needs to be differentiated from each other. Thus, decibel values were categorized into different types depending on the values to be compared. There are also decibel conversions that have a set reference power level where only a single power level is converted to a decibel value. Examples of these types of decibel conversions are dBm and dBW whose reference levels are one milliwatt and one watt, respectively. Voltage levels can also be converted to decibel values by changing the constant multiplier from 10 to 20. With this, decibel values become even more convenient as power levels are not easily measured. Furthermore, equations with voltages are readily available than power levels. There is also a unit related decibels called Nepers that is a unit to indicate gain and loss like attenuation but in an entity in itself.
Posted 2011-01-29 and updated on Jun 08, 2011 2:31pm by crisd