Design Aspects of an Antenna-MMIC Interface Using a Stacked Patch at 71–86 GHz

A bond-wire-free interconnection between monolithic microwave integrated circuit (MMIC) and antenna using a stacked patch configuration is investigated. An edge-fed patch on a gallium arsenide (GaAs) MMIC chip drives a patch antenna integrated in the lid of the MMIC package. The lid is formed using a liquid crystal polymer (LCP) substrate. The first implementation using a laminated multichip module (MCM-L) process is presented that covers the designated E-band spectrum for long-range wireless communications (71-86 GHz). Electromagnetic simulations and measurements of antenna radiation patterns agree well over the whole frequency range of interest. Important design aspects and manufacturing tolerances specific for the implementation of the interface in MCM-L millimeter-wave front-ends are presented. An alternative design is proposed for improved radiation patterns across the band.