A Multi-Beam Direction- and Polarization-Agile mm-Wave Front-End for 5G Communications

A millimeter wave multi-beam direction- and polarization-agile front-end for 5th generation of wireless communications at 30 GHz is presented. Active voltage summing was used for the lossless electronic rotation of polarization, thus enhancing the envisaged flexibility of 5G air interfaces. The front-end core comprises a low-temperature co-fired ceramic multilayer module, hybrid-integrated monolithic microwave integrated circuits, and an incorporated dual-polarized 4-element array antenna, altogether at a compact size of 74 mm × 74 mm. Antenna feed phases and polarization angles and states are electronically programmable. The front-end, completed by control circuit boards and a heatsink, exhibits an over-the-air gain of 50 dB and a noise figure of 4.1 dB. Measurement results comprising the polarization control and beamformer blocks are presented.