A Novel Approach to Measure and Characterize Radiation Patterns of Antenna-in-Package

Antenna-in-package (AiP) needs for 6G applications have notably highlighted the independent test requirement challenges of silicon-based integrated circuits (IC) and substrate/package due to differences in fabrication methodologies and timelines. Therefore, a methodology is required that enables the characterization of these elements independently, especially the antennas integrated into a substrate that does not have access to an active source. This paper discusses the millimeter-wave (mmWave) design, modeling, and characterization of a test vehicle that employs the antenna radiation pattern characterization technique at the package level using a waveguide. The test vehicle is fabricated using a two-layer flip-chip enhanced QFN (FCeQFN) package. It constitutes a wide band slot bow-tie antenna integrated with a transition that guides the signal inside the package. The transition is a via-less interconnect with an 18GHz of -10dB bandwidth with a minimum attenuation of 1.4dB in the WR5 frequency band. A detailed description of the test setup and measurement methodology are discussed for the first time with a simulation to measurement data comparison for the WR5 frequency band. Further, an improved version of this via-less transition designed in a modified version of FCeQFN, along with a proof-of-concept showing its bidirectional behavior for waveguide launch-in-package (W-LiP) application, is reported.