The new CX-4 is an ultra low noise FET preamplifier, operating in room temperature down to deep cryogenic environments (T = 4.2 K, liquid helium). It is an improved version of its predecessor NexGen3 KC05.

The setup is easy: simply connect the signal and bias voltages to the controller and you are ready to go. The CX-4 is designed for fully-automated plug-and-play functionality.

Key Features

• ultra low input noise (typ. 0.31 nV/√Hz @ 1 MHz)
• frequency range 1 kHz to 4 MHz
  or 14 kHz to approx. 30 MHz
• input impedance > 15 MΩ
• small size and tiny thermal load of only 300 μW per channel
• fully-automated plug-and-play room temperature controller included!

• data sheet 4 MHz version (pdf)
• data sheet 30 MHz version (pdf)
• application note: tuning fork in microscopy (pdf)

An example of the application of CX-4 are measurements of excess noise in the anomalous metallic phase in amorphous indium oxide by André Haug and Dan Shahar at the Weizmann Institute of Science, Israel, published 16 January 2024 in Phys. Rev. B 109, 014514:
DOI:10.1103/PhysRevB.109.014514, pre-print: https://arxiv.org/abs/2305.15931

The development of CX-4 has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 721559.