Antenna-in-Package of Lateral Cross-Dipole Elements for Endfire Dual-Polarized Radiation at Dual Millimeter-Wave Frequency Bands for 5G FR2 User Equipment Applications

A dual-band and dual-polarized antenna-in-package (AiP) design is proposed for 5G user equipment (UE) applications in the 28- and 38-GHz bands. The AiP design incorporates lateral cross-dipole elements to produce endfire radiation with dual-polarized, fan-shaped patterns for UE applications with dynamic orientations. The AiP prototype is fabricated for heat handling enhancement using the low-temperature co-fired ceramics (LTCCs) process. It stacks 14 thin dielectric substrates to form a 3-D radiator architecture on the intersubstrate interfaces. The AiP employs multiple antenna elements to achieve 1-D beam steering. Each lateral cross-dipole pair combines horizontally oriented dipole arms with vertical parallel plates to generate dual polarizations. Full-wave simulations indicate an approximate gain of 4 dBi for each antenna element, with broad and fan-shaped radiation patterns. These findings have been further validated through measurements conducted on an antenna prototype.