  5th Generation Mobile Network Systems(5G systems) operating in milli-meter
Wave (mmW) bands will employ base stations with integrated Active Antenna
Systems (AASs) capable of beam-tracking using narrow beams obtained from array
antennas encapsulated in a chip-like device. Regulatory limits for unwanted
Radio Frequency (RF) emissions are currently set in terms of Total Radiated
Power (TRP). As measurements at the antenna connectors are not possible,
Over-The-Air (OTA) methods for TRP of unwanted emissions are needed. The method
investigated here uses power density measurements on a spherical surface in an
anechoic chamber. Two major challenges with such a method are: need for large
number of angular points, and search for worst case antenna configuration per
frequency for electrically large devices at high frequencies. These challenges
are addressed by investigating the impact of correlation, sparse sampling, and
use of beam sweeping on the TRP estimate. Finally, it is investigated how and
in which spatial regions near-field tangential electric field measurements can
be used to assess TRP.
