An Efficient Ray-Tracing Approach for the Isolation Assessment of Co-Located Base Station Antennas at mmWave

Numerical evaluation and/or measurement campaigns are currently the only means of evaluating the isolation between antennas; in the former case, the simulation time and computational resources necessary can be burdensome, whereas the latter requires several weeks of work to be completed. Within this context, this article aims at presenting an effective methodology for the evaluation of the isolation between co-located antennas in a rapid computational time. The proposed method is based on the near-field equivalent representation of real antennas (Tx and Rx) combined with the ray tracing method for evaluating the field re-radiated by the source antenna on the receiver, hence the received power. The procedure is general and suitable to any type of antenna with any configuration and number of radiation elements. Moreover, antenna mechanical and electrical details are not needed, since only near field information is needed. Finally, it considers the presence of the support structure and surrounding obstacles. The methodology has been validated by full-wave simulations and measurements, yielding consistent and accurate results with an error that is below 2 dB in most of the cases, up to 6 dB for very low coupling values, indicating a high level of accuracy and reliability.