A Wideband Dual-Polarized Tightly Coupled Array with Compact Size for 5G Millimeter-wave Mobile Devices

A miniaturized dual-polarized smartphone antenna based on tightly coupled dipole array (TCDA), applying to 5 G millimeter-wave (mmW), is presented. The antenna element has a size of 2.94 mm x 3.05 mm x 0.94 mm and covers a bandwidth of 91.5% and 88.4% with VSWR<2 for pol-x and pol-y, respectively. To achieve low cost, compact size, and reduce the number of ports, a specific miniature feeding structure, using Gamma-shaped coupling probes, is applied. The proposed smartphone antenna consists of eight elements with a size of 23.8 mm x 3.5 mm x 0.94 mm. Experiments show that the TCDA can support a minimum realized gain of 9.51 dB and 9.07 dB for pol-x and pol-y, respectively, within 5 G mmW bands. To verify the design concept, TCDA is fabricated and measured, which achieves 60 degrees scanning without grating lobes. The measurement results demonstrate that the proposed antenna is well suited for future 5 G mmW mobile phones.