With this contribution, the results of the measurement campaign performed with a synchronously distributed antenna array testbed operating at the center frequency of 3.686 GHz are presented. For the first time, to the best of
the authors’ knowledge, the electric field distribution induced by coherent downlink transmission was experimentally assessed in the proximity of the target receiver using a calibrated electromagnetic field probe. This allowed to quantify the actual observed electric field gain and the shape of the electric field enhancement region around the target received. It was found that 16 transmitting antenna elements enhance the root-mean-square electric field level by about a
factor of two, in a 2.5λ neighborhood of the target receiver. In addition, a possible disruption of the propagation environment due to the probe movement was assessed through the real-time channel state information feedback.