Tunable microwave impedance matching to a high impedance source using a Josephson metamaterial

Carles Altimiras (1) , Olivier Parlavecchio (1) , Philippe Joyez (1) , Denis Vion (1) , Patrice Roche (1) , Daniel Esteve (1) , Fabien Portier (1)

1 SPEC - UMR3680 - Service de physique de l'état condensé

We report the efficient coupling of a 50 Ω microwave circuit to a high impedance conductor. We use an impedance transformer consisting of a λ/4 co-planar resonator whose inner conductor contains an array of superconducting quantum interference devices (SQUIDs), providing the resonator with a large and tunable lineic inductance L ∼ 80µ 0 , resulting in a large characteristic impedance Z C ∼ 1 kΩ. The impedance matching efficiency is characterized by measuring the shot noise power emitted by a dc biased high resistance tunnel junction connected to the resonator. We demonstrate matching to impedances in the 15 to 35 kΩ range with bandwidths above 100 MHz around a resonant frequency tunable in the 4 to 6 GHz range.

Domains: Physics [physics]

Carles Altimiras, Olivier Parlavecchio, Philippe Joyez, Denis Vion, Patrice Roche, et al.. Tunable microwave impedance matching to a high impedance source using a Josephson metamaterial. Applied Physics Letters, 2013, 103, pp.212601. ⟨10.1063/1.4832074⟩. ⟨cea-01479016⟩