A New Concept for Quasi-Planar Integration of Superconductor-Insulator-Superconductor Array Receiver Front Ends

Large format focal-plane superconductor-insulator-superconductor array receivers, which bring together the advantages of high-sensitivity, high-resolution spectroscopy, and broad field of view, are of growing importance in astronomical observation operating at millimeter/submillimeter wavelengths. The conventional array-construction technique based on building blocks of single-pixel modules, however, becomes prohibitively difficult when the pixel count or the pixel density increases. We frame a design concept, aiming to break through this barrier by planar-integrating the array front ends. This method features membrane-based on-chip waveguide probes and a buried-in local-oscillator distribution waveguide network. We have carried out a proof-of-concept study. The measurement results demonstrate the feasibility of the concept at \text{2} \,\text{mm} wavelength.