Intentional Radiator (IR
) – Device transmitting the RF signal (such as an AP).
– Power delivered by IR measured at the connector of the antenna (dBm units)
– Power radiated by the antenna (dBm units)
– Apparent power gain of antenna (focusing energy)
Gains and Losses
are additive (decibels): decibel ratio (power) =
0dBm = 1mw, 3dBm = 2mw,
6dBm = 4mw, 10dBm = 10mw, etc.
36dBm = 10dBm + 10dBm + 10dBm + 6dBm = (10)(10)(10)(4)mw =
Max of 1w for the IR, 4w EIRP
For every 3dBi above the 6dBi antenna gain,
reduce the IRP by 1dB from a 30dBm level (p. 29 –36 Ch2 CWNA Text)
Ant gain = 27dBi, find P-P
Max IRP = 30dBm - (27dBi –6dBi)/3
So Max IRP = 30dBm – 7dB = 23dBm, and
= Ant Gain + IRP = 27dBi + 23dBm = 50dBm =
50mw (FCC), 40mw (IEEE).
Indoor use only.
250mw (FCC), 200mw (IEEE). Indoor or outdoors.
1w (FCC), 800mw (IEEE).
IRP and EIRP