How EMF is calculated ?

EMF stands for electromagnetic fields, Electromagnetic field is a physical field produced by electrically charged object, the field can be viewd as the combination of an electric field and magnetic field.

Those EMFs are present everywhere in our environment – the earth, sun and ionosphere are all natural sources of EMF.

Even it is the case for wireless technologies such as WiFi,2G 3G OR 4G  and 5G, and in wireless technologies the EMF is mainly depending on EIRP 

EIRP is Effective Isotropic Radiated Power, also called the Equivalent Isotropic Radiated Power. In antenna measurements, it is the measured radiated power in a single direction 

 EIRP = Power (in dBm) + Antenna_Gain (in dBi)

Remarks :

• – EIRP can reach large value even with moderate power (if the antenna gain is large)
• – The massive MIMO solutions proposed by vendors are typically 200 W (53 dBm) and 23 dB of antenna gain => 76 dBm
• – This value (76 dBm) correspond to a theoretical value obtained with all the resources allocated to one single UE, with the most directive beam. Practically this situation never occurs
• – However, the use of massive MIMO means that the instantaneous EIRP and the resulting peak (non time-averaged) electromagnetic field (EMF) levels can be much higher than those for traditional base-station antennas

EMF (Electromagnetic field) corresponds to the Electric Field, which is given by (in free space) :          

 The security perimeter is given by the maximum allowed value of 61 V/m.  Hence, the security perimeter  is with d calculated in meter.

Examples:  with a 76 dBm (200W and 23 dBi of gain Massive MIMO antenna, in a distance of 10 m ,

With the same product, the safety perimeter is

For information for Capacity band 3400 – 3800 MHz the International limits id 61V/m

EMF exposure evaluation is related to antenna’s radiated power over 6 min