Feeding Techniques for Multilayer PCB Mmwave Array Antenna for UE

In this paper, two different feeding techniques for patch antenna placed on a multi-layer PCB build-up are studied. Antenna design target 5G n258 band. Despite the losses in the inner layers, the patch feeding based on aperture coupling has a radiation efficiency higher than 70%. A second design using via direct feeding show similar performance, given the same antenna’s height. An $4 \times4$ array has been simulated and fabricated. The experimental results agree well with simulated ones, providing a 13 dB realized gain and a scanning angle of 90° large.