An impedance tuner is a critical component in a noise parameter measurement setup, as it allows a user to vary the source impedance presented to a device under test and measure the resulting noise power, from which the noise parameters are extracted.

While electro-mechanical impedance tuners are commonly used, they are not suited for cryogenic measurements as they cannot function within a cryogenic environment (i.e., cryostat, cryogenic probe station) due to their large size, mechanical operation, and the amount of heat created.  

Solid-state tuners provide a good alternative when purpose-designed for cryogenic impedance tuning.  The CT-series cryogenic automated tuners use electronic components rated for use at cryogenic temperatures below 4K to present electronically varied impedance states to a DUT. At under 80 grams, 60mm x40mm, and consuming less than 0.2mW, is ideally suited for operation inside a cryogenic environment.

An integrated temperature sensor ensures the precise temperature inside the tuner is known.  An integrated bias tee allows for the optional biasing of the DUT source, while external biasing can be used to bias the load of the DUT.