Microwave Filter and Thermalizer
Designed for mili-Kelvin and
sub-mili-Kelvin experiments
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Microwave filtering and thermalization of signal wires are two critical ingredients in setting up a sensitive low-temperature experiment. Our compact cryogenic microwave filter and thermalizer (MFT) unites efficient electron thermalization with ultra-strong microwave attenuation.
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MFTs consist of a copper or other low-resistivity wire embedded in a highly conductive silver matrix. The silver matrix acts as a heat exchanger ensuring optimal thermalization.
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The superior performance of single MFT filters was proven in an experiment that cooled a Coulomb blockade thermometer down to 7.5 mK with a dilution fridge temperature at 5 mK (ref: Scheller et al. APL 2014).
Strong attenuation and thermalization
Low capacitance and low resistance
Strong attenuation of >100 dB
above 130 MHz
~100 Ω & 2.5 nF @ 4K or
~25 mΩ & 2.5 nF @ 4K
Low capacitance for low noise
Low resistance for high current applications
> 1 TΩ resistance to ground
> 100 V maximum applied voltage
Single MFT filters
SMA, MCX connectors or customized
Length 30 mm
Diameter 6 mm
Compact filter box
25 filters inside
Micro-D connectors
Non-magnetic copper box, gold-plated
for best thermal contact
Easy to mount at 10 mK
30 x 56 x 68 mm, 400 gr
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NEW: 2-pole RCRC stage option with 3dB cutoff down to kHz, integrated into the same compact box (see datasheet for full details)
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kHz cutoff with 2-pole RCRC stage
Integrated into the same compact MFT25 box
Standard cutoff options from 1 to 35 kHz
Customized cutoff with application
dependent R and C
See datasheet for full details
Slim MFT package for small cryostat inserts
Each package includes 8 lines
Several packages can be stacked
on top of each other
Up to 6 packages (48 lines) fit in
a 50 mm insert
51 x 21 x 3.2 mm
SIP-socket connectors for easy plugging/unplugging
Easy mounting on cold finger