Design of D-Band MMIC-WG Contactless Transition Based on Silicon Process

Paper in proceeding, 2025

A D-band contactless monolithic microwave integrated circuit to waveguide (MMIC-WG) transition is proposed in this paper. An on-chip bowtie launcher is utilized to realize coupling to the rectangular waveguide with good mode and impedance matching. The process used is a customized silicon-based one, with two aluminum metal layers and one silicon-dioxide layer. It can be proved that the transition performance is influenced by metal conductivity and silicon resistivity. Due to a shorted end at the coupling region, the waveguide thru-mode is suppressed well. In addition, to reduce leakage from split waveguide blocks, a step structure is introduced, and the effect is demonstrated by measurement. The proposed transition is fabricated, assembled and measured, showing 1.1 dB insertion loss and 113.9−150.5GHz bandwidth with good simulation and measurement agreement.