Cryogenic Passive Attenuator and Termination

Many of the Fixed Attenuators and Terminations now being sold are not stable at cryogenic temperatures.  XMA provides several Cryogenic Compatible, Coaxial Fixed Attenuators and Terminations.  These items are being sought after by many prestigious colleges and universities around the word such as Harvard, MIT and Yale. Many universities and colleges performing research on microwave designs/products requiring signal attenuation or termination. 

Cryogenic, Super Low Temperature and Superconductivity

Our resistive circuit materials are well suited with Low TCR/TCA and will not super-conduct when exposed to temperatures near zero Kelvin.  The resistor film and conductors to ceramic adhesion needs to be superior to not fracture with the severe material contractions expansion over the more than 300 degree ranges it will be subjected to.  The circuit design needs to have stable attenuation by having all resistors vary in resistance equally during the temperature changes to maintain stable attenuation (low thermal coefficient of attenuation - TCA).  XMA utilizes a film for its cryogenic attenuators of a proprietary alloy that resulted from several years of research performed at Omni Spectra that resulted in the alloy we continue to use today.  Our devices often approach Class III levels (MIL-DTL-3033) even at cryogenic temperatures.

The extreme Temperature Coefficient of Expansion issues require a rugged design that survives the extreme thermal shocks.  The mounting of the attenuator circuit in the housing needs to allow for contraction and expansion while maintaining excellent electrical contact.  XMA’s unit has interconnects that allow this to occur seamlessly without “chatter” or noise occurring.  The connector captivation must stand up to this environment as well.

The connector varieties offered includes SMA, 2.92 mm, 2.4 mm, Type N, and TNC in power levels up to 5 watts with research expanding offerings all the time.  All units are broadband products usable from DC up to 50 GHz (depending on selection of product) at all times.  We can also make these as one of our “Adapttenuators” with differing input and output connectors and sexes.  Many of our terminations use a 30 dB attenuator chip, which yields excellent low VSWR using a single port for termination.
  • Captive Resistive Thin-film Hybrid Fab Lab
  • Proprietary thin-film hybrid is unique to Omni Spectra® components
  • Temperature Coefficient of Resistance (TCR’s) of < 15 ppm/°C prevent superconducting at cryogenic temperatures
  • Benefits include stability, ultra-low noise, & high power density
Contact your local distributor, representative or direct to the factory with your needs and questions.
    • cryo