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.