Bi-Layer Kinetic Inductance Detectors for W-Band

A superconducting kinetic inductance detector (KID) has been fabricated and it has demonstrated absorption at W-Band. The use of a bi-layer structure based on aluminium (Al) and titanium (Ti) demonstrates a lower superconducting critical temperature (Tc), which allows the detection at W-band. A design methodology is presented taking into account the KID geometry in order to maximize the absorption. A dual-polarization KID has been designed using the proposed methodology. Two prototypes of KID on Silicon substrate have been fabricated showing a good agreement between measurement and simulation results. The measurements at room temperature from 65 to 110 GHz show the matching at the frequency band, while dark cryogenic characterization demonstrated the low frequency design.