Mechanically Decoupled Transitions from MMIC to Rectangular and Dielectric Waveguides at G-Band

A variety of transitions from a monolithic microwave integrated circuit (MMIC) to a waveguide were proposed in literature to enable chip-to-chip links or to provide a standard interface. The MMIC is usually in contact with the waveguide and is therefore exposed to the mechanical stress exerted on the overall system. This paper presents mechanically decoupled transitions from MMIC to a rectangular waveguide and to a dielectric waveguide at G-Band (140GHz to 220 GHz). Both transitions use a patch radiator on a quartz glass carrier as on-chip antenna. To focus the beam, a dielectric rod antenna or an elliptical dielectric lens is placed on the quartz glass. Since the transitions are mechanically decoupled, a second antenna is used as receive element. A horn antenna connected to the rectangular waveguide or a second dielectric lens connected to the dielectric waveguide is used. The transitions were characterized using a back end of line MMIC. The minimum measured insertion loss is 3.1 dB for the transition from MMIC to rectangular waveguide and 4.9 dB for the transition to dielectric waveguide.