Millikelvin thermal and electrical performance of lossy transmission line filters

Slichter, D. H.; Naaman, O.; Siddiqi, I.

Millikelvin thermal and electrical performance of lossy transmission line filters

Authors

Slichter, D. H.

Naaman, O.

Siddiqi, I.

Description

We report on the scattering parameters and Johnson noise emission of low-pass stripline filters employing a magnetically loaded silicone dielectric down to 25 mK. The transmission characteristic of a device with $f_{-3dB}$=1.3 GHz remains essentially unchanged upon cooling. Another device with $f_{-3dB}$=0.4 GHz, measured in its stopband, exhibits a steady state noise power emission consistent with a temperature difference of a few mK relative to a well-anchored cryogenic microwave attenuator at temperatures down to 25 mK, thus presenting a matched thermal load.
4 pages, 4 figures