Dual-band and Dual-polarized Rhombic Patch Antenna Array for 5G mmWave RF Front-end Antenna-in-Package (AiP) Module

This paper proposes a novel rhombic dual-polarized and dual-band patch antenna array design for 5G mmWave mobile devices as an antenna-in-package (AiP). The proposed antenna consists of a stacked patch and a parasitic patch that are designed to operate at dual frequencies (28 and 39GHz). An asymmetric stack-up strategy is used to maximize antenna performance within the constraints of the form factor. To address the limitations of elongated asymmetrical structures, the rhombic patch is utilized to achieve dual-polarization capabilities. The RF front-end module (RFFE), which integrates the proposed AiP (1×4 array antenna), is also fabricated and tested for its gain and beam-steering performance. The results show a maximum gain of 10.4 dBi at the lower band (LB) and 11.0 dBi at the higher band (HB) with beam-steering capabilities of ±45 degrees in both bands.