5G was pervasive theme at many booths at MWC Barcelona 2018.
Massive MIMO, multiple input multiple output antennas, are a key technical innovation required by 5G. Various antenna vendors demonstrated massive MIMO antennas from 16T16R up to 64T64R but it looks like antenna vendors are taking different approaches to addressing the challenges of 5G.
Kathrein, Huawei and Commscope demonstrated novel active passive antennas (APAs) at MWC Barcelona 2018. Crucially these APAs incorporate the massive MIMO antenna array into the same antenna housing as the passive multiband antenna elements that handle transmissions on a range of low (sub 1 GHz) and high (1 GHz to 2.x GHz) frequencies.
Antenna vendor, Rosenberger, has been innovating a range of ultra thin, omni-sector 5G/4G antennas as well as compact massive MIMO antennas that are particularly suited to urban environments.