Hybrid Switchable Phased Array with p-i-n Diodes for 5G Mobile Terminals

This article proposes a compact hybrid beam-switchable phased array, with simple structure, high gain and large coverage in the mm-wave band, for next generation mobile handsets. Four reconfigurable antennas are selected as array elements, consisting of two monopoles, placed on both sides of the short clearance of 3 mm, fed by SIW. Each array element has three p-i-n diodes controlled working modes, which generate three switchable radiation patterns, two broadside, by switching on either the top or the bottom monopole, and one endfire, given by all the p-i-n diodes in off state. While the beam-switching is realized in the φ plane, the beam-scanning is achieved in the θ plane through progressive phase shifts. The array has -10 dB impedance bandwidth of 3 GHz from 27 to 30 GHz, which is a portion of the 5G spectrum. Simulations including the proposed hybrid antenna system, placed on the top left corner of a mobile phone PCB, prove that the three switchable beams cover the angle range of ±75° in elevation, while the scan angle of ±30° in azimuth is covered by beam-scanning, obtaining overall 3D coverage with realized gain higher than 7 dBi at 28 GHz.