Co-Design of Chip-Package-Antenna in Fan-out Package for Practical 77 GHz Automotive Radar

This paper presents a co-design of chip-package-antenna in fan-out package for automotive radar. Many packaged chips are directly soldered onto the feeding network of planar antenna array. However, the interconnections and associated radiation interferences are seldom considered. Thus co-design of chip-package-antenna is necessary since the radiation pattern is seriously affected by the packaged chip and feeding network, especially at millimetre-wave frequency. In this work, the used antenna is a planar 12-element series-fed linear antenna array. Based on Dolph-Chebyshev magnitude distribution, the desired radiation pattern is firstly synthesized by tapering each patch width. Then the transition of chip-package-board is proposed and realized by properly designing redistribution layer (RDL) in fan-out package and the GCPW line on PCB. After chip is flip-chipped onto antenna, the side lobe level (SLL) of the whole chip-package-antenna gets worse. By redesigning the width and distances of between elements, the SLL can be improved. The results show that the proposed method of chip-package-antenna paves the way to practical automotive radar application.