Novel Antenna-in-Package Design Based on Endfire Radiation Subarray Decomposition to Format Broadside Array at Sub-THz Frequencies

A novel antenna-in-package (AiP) of a 2-D array is proposed for sub-terahertz (Sub-THz) applications at the 250–310-GHz band. The 2-D array is decomposed into several 1-D row subarrays realized on a multilayered dielectric-substrate panel. To produce sufficient space for active RF transceiver module accommodation, the 1-D row subarrays are designed to radiate endfire patterns from along the edge direction of the dielectric panel such that the space behind the antenna can be freely used with limitations. Afterward, several panels of the 1-D row subarrays are stacked vertically to form the 2-D AiP array by utilizing glued dummy wafers (GDWs) or low-temperature soldering (LTS) ball grid arrays (BGAs), whose thickness may produce a cavity to accommodate the RF transceivers and build the RF signal paths in AiP operation. After the stack up of forming a rectangular array, the antenna is turned around by 90° to face upward, which transforms the endfire radiation into a broadside one, as desired by the ordinary AiP. This AiP has dual-linear polarization (dual-LP) radiations that can align with the base station antenna for polarization matching. Full-wave simulations are presented to demonstrate the design concepts, where measurement results of a 1-D row array are also presented to validate the design and exhibit the radiation characteristics.