AlexandrP,
The 3805i access point is purpose built to operate in the unlicensed 2.4Ghz and 5Ghz bands which are defined for each regulatory domain. In that sense they emit or receive radio frequency emissions and must inter-operate with other devices in the same spectrum. It is unlikely you will be able to utilize the minimal functions of the cli console in a standalone mode to perform any RF measurements without some modifications. Perhaps you could further elaborate on the nature of the radiation power you would like to monitor. There are other tools such as spectrum analyzers which may be better suited.