Co-Design of Dielectric Resonator-Based Antenna-in-Packaging in FOWLP Technology: Addresses warpage and die shift during fabrication

This article presents a comprehensive co-design approach for dielectric resonator antenna (DRA)-based antenna-in-packaging (AiP) solutions utilizing fan-out wafer-level packaging (FOWLP) technology. Despite the advantages of high-precision wafer-level fabrication and advanced integration capabilities with multiple redistribution layers (RDLs), traditional planar antenna-based AiP structures are often unsuitable for FOWLP because of potential warpages caused by the heating processes. By contrast, DRAs offer high radiation efficiency and effective warpage control through strategic sizing of the radiator and the distribution of dummy antenna dielectrics within the module. We evaluate the robustness of the proposed AiP design against fabrication errors through rigorous electromagnetic (EM) simulations, providing comprehensive design guidance. We employ symmetrical feeding techniques to mitigate the effects of antenna die misplacement. This dual-feed configuration enhances the antenna’s resistance to die shift and allows for greater pattern diversity. We discuss an optimal dimension ratio that addresses thermomechanical issues while enabling dual-mode operation through proper excitation of the higher order transverse electric modes <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\text{TE}}_{\delta{13}}^{x}$</tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\text{TE}}_{\delta {21}}^{x}$</tex-math></inline-formula>. The proposed antenna was fabricated using a 6-in FOWLP process, achieving a wafer-level warpage of less than 0.5 mm. Measured peak realized gains of 7.38 dBi for broadside radiation patterns and 6.1 dBi for monopole patterns were obtained at 140 GHz. The effectiveness of the FOWLP AiP concept has been validated through experimental results, demonstrating its potential applications in millimeter-wave (mmWave) communication and radar systems.