Dual-Band and Dual-Polarized Rhombic Patch Antenna Array for 5G mmWave RF Front End Antenna-in-Package Module

This letter proposes a novel rhombic dual-polarized and dual-band patch antenna array design for 5G millimeter-wave (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 39 GHz). 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 and 11.0 dBi at the higher band with beam-steering capabilities of ±45° in both bands.