Metamaterial-Enabled Ultrawideband mmWave Antenna-in-Package Using Heterogeneously-Integrated Silicon IPD and HDI-PCB for B5G/6G Applications

This work presents the design, creation, and testing of ultrawideband millimeter-wave (mmWave) antennas with a tightly coupled array (TCA) configuration. These antennas are made using metamaterial (MTM) designs and advanced high-density interconnect (HDI) antenna-in-package (AiP) technologies, ideal for beyond-5G (B5G) and 6G networks. The main elements of the MTM antenna array are constructed with silicon-based integrated passive device (IPD) technology and are flip-chip bonded to a multi-layered HDI-PCB that includes a resistive frequency selective surface (FSS). These array antennas are differentially fed through a coax-via system. The study presents two types of 5×5 finite arrays: a metal-insulator-metal (MIM) capacitor-based MTM bowtie array with a differential Voltage Standing Wave Ratio (VSWR) ≤ 3.5, operating from 16.2 to 100 GHz (excluding 18.26 – 18.68 GHz and 60.8 – 61.13 GHz), and an interdigital capacitor-based MTM bowtie array functioning from 18.85 to 100 GHz (excluding 41.52 – 42.25 GHz). Experimental validation of these prototypes confirms their performance, aligning well with simulated results in terms of bandwidth and radiation characteristics.