Silicon Taper Based $D$ -Band Chip to Waveguide Interconnect for Millimeter-Wave Systems

This letter presents a novel interconnect for coupling millimeter-wave (mmW) signals from integrated circuits to air-filled waveguides. The proposed solution is realized through a slot antenna implemented in embedded wafer level ball grid array (eWLB) process. The antenna radiates into a high-resistivity (HR) silicon taper perpendicular to its plane, which in turn radiates into an air-filled waveguide. The interconnect achieves a measured average insertion loss of 3.4 dB over the frequency range of 116–151 GHz. The proposed interconnect is generic and does not require any galvanic contacts. The utilized eWLB packaging process is suitable for low-cost high-volume production and allows heterogeneous integration with other technologies. This letter proposes a straightforward cost-effective high-performance interconnect for mmW integration, and thus, addressing one of the main challenges facing systems operating beyond 100 GHz.