High-Throughput Microwave Package for Precise Superconducting Device Measurement

Cryogenic microwave measurements of superconducting devices are often limited by the complexity of their packaging. We present a wire-bond-free, PCB-free, drop-in microwave package for on-chip superconducting devices. The package uses a superconducting aluminum cavity with a suspended tungsten pin for signal transmission. The cavity mode is well detuned from the 4-8 GHz range, and the transmission ripple is below 3 dB. Using this design, we measure the dielectric loss tangent of superconducting ring resonators as (1.15±0.04)×10^-6. This high-throughput platform enables fast, repeatable measurements across many devices and supports studies of oxide regrowth, and material improvements for superconducting devices.