Antenna Array on Glass Interposer for 6G Wireless Communications

Abstract

This paper demonstrates integrated packaging solutions for antenna components in D-band by using glass-based package. We design sub-terahertz patch antennas at 140 GHz frequency band using HFSS simulation, and form arrays of patch antennas for 6G (sub-THz) wireless communication applications. The patch antennas and feeding networks are implemented using microstrip structures on the top of the interposer, with ground planes beneath. Build-up layers of polymer dry films are laminated on a glass core for multi-layer copper metallization, and copper structures are patterned on the polymer layers. For precise fabrication of the antenna and feeding structures in package, we implement the semi-additive patterning process to deposit the copper structures. Adequate measurement methods are applied to address difficulties in D-band antenna measurements. By forming patch antenna arrays, we obtain 10 dBi gain using a 4-element linear array and 14 dBi gain using a 4-by-4 2-D array. The bandwidths achieved for these arrays are 7% (10 GHz) and 5% (7 GHz), respectively, based on return loss measurements. Overall, the measurement results present good match to simulation. Antenna structures on glass substrates demonstrated in this paper represent the basic building block for heterogeneous integration of D-band front-end module in glass-based packages.