Tunable microwave impedance matching to a high impedance source using a Josephson metamaterial
Abstract
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]
Origin : Files produced by the author(s)
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