Planar Asymmetric Fed Interdigital Coupling Antenna-in-Package Using FOWLP Process Operating at 60–90 GHz in Endfire Mode

Abstract

This article first reports a wideband asymmetric fed interdigital coupling antenna (AFICA) with the fan-out wafer-level package (FOWLP) process. The asymmetric fed structure is designed to realize a more compact array size. The interdigital-shaped coupling method between the elements achieves wideband impedance matching with 70- feeding line. In addition, the exemplified 1 4 AFICA array package demonstrates a wide bandwidth from 60 to 90 GHz and an extremely low profile of 0.044 at 60 GHz. Furthermore, the prototype module is fabricated and integrated with frequency quadrupler CMOS chip. The measured results exhibit a wide bandwidth from 60 to 90 GHz and a peak gain of 9.3 dBi. The measured antenna efficiency is higher than 80%. Both fabricated package and module feature a wide scanning angle of and low cross-polarization levels ( dB) at operating bands, respectively. The power-based de-embedding method is proposed to evaluate the performance of real-life modules and systems. The simulated and experimental results of the fan-out (FO) interconnection loss are less than 1 dB, respectively. As a result, the proposed co-planar wideband AFICA array with endfire mode design is fully compatible with various chips, such as 5G/6G communication, radar, and sensing applications. IEEE