Novel Integrated Design of a Dual-Band Dual-Polarization 5G mm-Wave Antenna Array Fed by FPCs with a U-Slotted Full-Metal Case for a Cellular Phone

A novel design of a dual-band dual-polarization millimeter-wave (mm-Wave) antenna array fed by a flexible printed circuit (FPC) integrated into a full-metal casing with U-shaped slots of a cellular phone for the fifth generation mobile communications (5G) is proposed. This integrated and conformal design is also promising to the future potential attractive antenna solution of mm-Wave antennas in non-mm-Wave antennas (AiA) especially when a metal frame or a metal casing is applied to the exterior of a cellular phone. The novel mm-Wave antenna array is based on 5 dual-band dual-polarization stacked patch antennas embedded in the metal exterior and the antenna array is fed by one FPC with 10 traces for dual polarizations of each antenna element. Owing to the ground shading of the recessed metal cells for the stacked patch antennas, the performance of the antenna array will be not so susceptible to the components or structures behind the integrated metal structures. Bases on simulations, in terms of the input reflection coefficients| S
_nn
| ≤ -10 dB, the bandwidths of the ports (V-ports) in the mm-Wave antenna array for the vertical polarization (V-pol.) range from 27.43 GHz to 28.49 GHz and from 36.29 GHz to 40.05 GHz, respectively; similarly, the bandwidths of the ports (H-ports) in the mm-Wave antenna array for the horizontal polarization (H-pol.) range from 27.36 GHz to 28.46 GHz and from 36.64 GHz to 41.71 GHz, respectively. In other words, the two popular 5G mm-Wave bands of n261 (27.5-28.35 GHz) and n260 (37.0-40.0 GHz) in the third generation partnership project (3GPP) therefore can be accommodated. The maximum (max.) V-pol. peak realized gains in the low band (band n261) and high band (band n260) are 10.10 dBi and 11.21 dBi, and the max. scanning angles are both 45°. Similarly, the max. H-pol. peak realized gains in the low band and high band are 10.26 dBi and 10.57 dBi, and the max. scanning angles are 60° and 30°, respectively. The antenna array also can achieve right-hand and left-hand circular polarizations.