W-Band High-Gain Glass-Based Substrate-Integrated Cavity Antennas for Heterogeneous Integration Applications

This study presents a gain-enhanced substrate integrated cavity antenna that operates in the W-band. First, the radiator’s mode is analyzed, after which a pair of patches with shorting pillars is symmetrically designed to reduce the profile and tune the impedance without affecting the antenna’s radiation performance. A gain improvement of 3.9 dB is obtained by optimizing the length of the radiator. The radiator is then bonded on a silicon interposer on which a benzocyclobutene-based coplanar waveguide with ground to glass-based SIW transition structure is designed by considering low-loss interconnections. Thereafter, a 1×1 glass-based antenna and a 1×4 antenna array were fabricated using through-glass via technology. Results showed peak gains of 10.2 and 14.7 dBi with bandwidths of 25.6% and 31.5%, respectively. The proposed antennas can be further integrated three-dimensionally with other active components.