Integrated 122-GHz Antenna on a Flexible Polyimide Substrate With Flip Chip Interconnect

A packaging solution for the integration of an MMIC and a thin film antenna into a single surface-mountable package is presented. It is based on an air cavity in the package base into which the MMIC is placed. All package-to-MMIC interconnects are routed through the antenna substrate and all connections are realized using flip chip technology. Thus wire bonds are eliminated within the whole package. A broadband flip chip interconnect is used to connect MMIC and antenna. As the antenna is situated above an air cavity, a large bandwidth is also achieved for the antenna. An antenna-in-package prototype is presented to demonstrate the feasibility of the assembly process and to test the antenna performance including the flip chip interconnect. The influence of an additional package cover is analyzed by measuring the antenna covered with two different lids.