Superconducting on-chip tunable mm-wave resonator

We present a design of a tunable on-chip resonator that can benchmark the nonlinear kinetic inductance (KI) properties of various superconducting thin films in the W-band (75-110 GHz), for quantum device applications. Our design uses a quarter-wavelength microstrip resonator with ground plane cutout for transmission measurements, WR10 input & output ports, DC bias line and radial-stub notch filters to suppress RF leakage into the bias lines. Our resonator design procedure uses simulations with perfect electric conductors as an initial reference case, which will be later replaced by finite-impedance material to include the effect of sheet inductance.