Module, antenna, and package design considerations for mm-scale IoT devices

This paper presents a study of antenna-in-package (AiP) design options for mm-scale Internet-of-Things (ioT) applications. Specifically, silicon interposer and organic-based substrates with areas ranging from
$2.1\times 2.1$
mm
²
to
$6\times 5$
mm
²
are explored as options to package a mm-scale active IoT IC and integrate it with antennas to form a compact module capable of power harvesting and data transmission. The AiP designs considered are electrically-small loop and dipole antennas operating at 900 MHz and 5.8 GHz in the sub-6 GHz bands as well as dipole antennas operating in the 28 GHz mm-wave band. Simulation results show that AiP designs in both silicon interposer and organic-based substrates can achieve similar performance; moreover, we also observed that for a given EIRP limit, 28 GHz achieves the highest range for smaller
$2.1\times 2.1$
mm
²
substrates. Initial measurement results on fabricated AiP test structures and complete IoT module samples show the feasibility of electrically-small antenna designs for these applications and highlight associated fabrication, assembly, and measurement challenges.