A Wideband Dual-Polarized Antenna-in-Package for 5G Millimeter-Wave User Equipment

This article presents a broadband dual-polarization antenna-in-package (AiP) design for 5G millimeter-wave user equipment. The magnetoelectric (ME) antenna is adopted to achieve dual polarization and broadband. We introduce a tapered feeding probe to enhance the antenna’s dual-polarization isolation and optimize the impedance matching between the feeding network and the radiating patch to achieve high gain throughout the entire operating bandwidth. Based on the antenna element, we design a $1\times 4$ antenna array with the dimensions of $20\times 5\times 1.1$ mm3. The impedance bandwidth of both polarizations of the array falls within 26.8–42.7 GHz, covering the majority of the 5G new radio (NR) bands. The gain range for horizontal polarization within this band is 9.87–12.5 dBi, while that for vertical polarization is 10.67–12.51 dBi. The antenna array can achieve the beam-scanning angles of 50° and 30° in the FR2 n257 and n260 frequency bands, respectively. The AiP is manufactured and tested using the flip-chip ball grid array (FCBGA) process on an organic substrate, with the test results closely aligning with simulation outcomes. The proposed AiP covers 5G millimeter-wave n257, n259, n260, and n261 bands and a significant portion of n258 (24.25–27.5 GHz) while guaranteeing high dual-polarization isolation and considerable gain, thus making it suitable for application in 5G millimeter-wave user equipment.