Gapwaveguide Automotive Imaging Radar Antenna with Launcher in Package Technology

Journal article, 2023

A 77 GHz gapwaveguide radar antenna system with launcher-in-package (LiP) technology is presented in this paper for automotive imaging applications. Firstly, state-of-the-art LiP technology integrated with radar transceivers is proposed. The transceivers are equipped with waveguide interfaces for RF connection, enabling direct integration with waveguide antennas. Robust interconnects for coupling transceivers to waveguide antennas with non-galvanic contacts are proposed using gapwaveguide packaging technology. A simultaneous multi-mode imaging radar system using 4 cascaded aforementioned transceivers is introduced. Designated antenna elements of the system are realized by slot arrays with center-fed ridge gapwaveguides. Ultimately, the imaging radar antenna has a top radiating slot layer, a middle distribution layer and a bottom interconnect layer capable of accommodating 4 LiP radar transceivers with considerable assembly tolerance which is really one of the key aspects for commercial automotive radar applications. Input matching and radiation patterns of the antenna are verified by measurement. The results indicate that the proposed gapwaveguide imaging radar antenna in conjunction with the novel LiP packaging is able to serve the radar system properly. To the best of the authors’ knowledge, the proposed gapwaveguide antenna system is the first imaging radar antenna system ever developed for LiP components. This work provides a compact, high-efficiency and cost-effective solution for the integration of complex radar systems with waveguide antennas.