Design and Simulation of a Ultra-Wideband 211-375 GHz SIS Mixer based on a Micromachined Metallic Substrate

Paper in proceeding, 2024

In this paper, we describe the design and simulation of a novel ultra-wideband SIS mixer for radio astronomy applications, specifically to cover the ALMA telescope's bands 6 and 7 corresponding to an extensive 56% fractional bandwidth. The design features an electroplated metallic substrate that integrates a finline waveguide-to-substrate transition. Furthermore, the design employs a twin-junction SIS configuration with an Al/AlN barrier. The simulation of the RF matching circuit predicted a 93% coupling efficiency across most of the band. Additionally, this paper details the development and simulation of an integrated IF output circuit, optimized for the 4-16 GHz band. The simulation of the IF output circuit shows the losses in the IF coupling are better than 0.3 dB for most of the band and a reflection coefficient for a 50 Ω output impedance of -15 dB.