Engineering Expertise for Space CommunicationsWith over 15 years experience in cryogenic applications, Callisto is able to offer high precision and cost effective cryogenic test equipment and services, for a wide range of applications and sectors.
Callisto’s Dewar (cryostat) has been designed in particular for the testing of RF and microwave components at cryogenic temperatures down to 15 Kelvin. The Dewar is equally well adapted for testing any electronic circuit, processor or small mechanical components. The Dewar solution enables a vacuum environment and uses a two stage closed cooling cycle Helium refrigerator.
Connection to the external world can be made to the test component by means of a number of optional and re-configurable access ports in the walls of the Dewar. Coaxial and/or waveguide test ports may be used depending on the application. Low thermal loss transmission lines are used inside the Dewar to ensure optimum thermal isolation. Some additional multi-way electrical connections are also available for control, signalling or power circuits. The Dewar is equipped with internal thermometers linked to an external computer for logging purposes. The computer and logger can also record analogue or digital parameters from the test bench, in case that the recording of measured parameters as a function of temperature is required.
The maximum component size which can be accommodated is defined by the cold station enclosure size of 300mm x 300mm x 100mm.
| Test Dewar Specifications | |
| Base Operation Temperature | First Stage < 50 Kelvin, Second Stage < 15 Kelvin unloaded |
| Test Enclosure Environment | Vacuum < 10 -6 Torr |
| Dewar Material | Aluminium |
| Cold Plate Material | Aluminium; Nickel plated |
| Cold Plate Dimensions | 300 mm x 300 mm (width/length) |
| Cooldown and Warm-Up Times | ~4 hours cooldown time, ~4 hours warm-up time (using integrated heating circuit) |
| Internal clear height above cold plate | 100 mm (with extension tube to give > 150 mm clearance for direct RF feed testing (e.g. satellite feed)) |
| Cooling Power | First Stage 8 Watts, Second Stage 6 Watts |
| Test Duration | ~10,000h – closed cycle refrigerator |
| Test Ports | Up to 7 optional ports of 80-200 mm for waveguide, coaxial RF, direct RF feeds or other types of inputs. |
| Thermometry | Silicon Diode cryogenic thermometers on first and second stages. |
| External logging | Up to 20 analogue channels and 16 digital lines. Analogue parameters sampled at 60 readings/second (max). PC based data written to ASCII file. |
| Mass | ~45kg |
| Accessories | Support trolley |
Callisto’s test service offer allows clients a flexible solution to evaluate the performance of components at cryo temperatures, priced on a per-test basis and minimising capital expenditure. The comprehensive service includes:
A complete RF Test bench is available to clients for their own in-house component testing. The test solution includes the above described Dewar, cryo-cold head, cryo-compressor and vacuum pump.
The re-configurable access ports include a large 200 mm vacuum window on the top plate made of Mylar and PTFE, ideal for IR direct signal reception (e.g. a satellite feed). The window and its extension tube can be removed and replaced by a metal blank plate with sealing ring.
