Joint-Stock Company "Saturn" has developed the series of ultra-low-noise receivers and radiometers, cooling to cryogenic temperatures and operating in frequency range from 1.0 up to 43 GHz with 5-45 K noise temperature.
      It is possible to use a cooled mixer at the device input. In this case the operating frequency range can be widened up to 300 GHz.

      Ultra-low-noise receivers are executed on base of cooled up to 12-15K of the transistor amplifiers, in which are installed the high electron mobility transistors (HEMT).
      The cooling of transistor amplifier and input path is provided by microcryogenic closed-type system of hydrogen level.
      The radiotelescopes RT-22, RT-70 (Ukraine), RATAN-600, RT-64, RTF-32 (Russia), and also the radiotelescopes with dish 25-m diameter in Shanghai and Urumgi (China) are equipped with the radiometers developed in "Saturn".
      Input microwave channels of the devices in 1.5-2.3GHz range are performed on the base of 7/3 mm coaxial line; in other ranges - on the base of standard rectangular waveguides. The output microwave channels in 1-18 GHz frequency range are performed on the base of 3.5/1.5 mm coaxial line; in other ranges - on base of standard waveguides.
      The ultra-low-noise receiving SYSTEMS are not serial products, and its are manufactured according to individual order under particular tasks. The estimated cost of such system from $80.000 up to $320.000, depending on reguired kits and ordered frequency range.

THE MAIN PARAMETERS OF RECEIVERS

Fo, GHz	F, %	Noise temperature, K	Gain, dB	VSWR in/out	Quantity of case.
1,5	15	6	35	1.3/1.5	2
2,3	15	7	35	1.3/1.5	2
3,7	15	6	30	1.3/1.5	2
4,8	15	7	30	1.3/1.5	2
7,5	15	9	30	1.3/1.5	3
8,5	15	10	30	1.3/1.5	3
11,2	15	12	30	1.3/1.5	3
22,0	15	20	30	1.3/1.5	3
30,0	15	25	28	1.3/1.5	3
37,0	15	30	30	1.3/1.5	4
43,0	15	35	28	1.3/1.5	4

THE MAIN PARAMETERS OF RADIOMETERS

Designation	Frequency range, GHz	IF range, MHz	Noise temperature, K	Gain, dB
CS 022101	1,38 - 1,72	100 - 440	6	55
CS 022102	2,15 - 2,50	100 - 450	7	55
CS 022103	4,60 - 5,10	100 - 600	7	55
CS 022104	8,18 - 8,68	100 - 600	12	55
CS 022105	22,0 - 22,5	100 - 600	25	55

ULTRA-LOW-NOISE CRYOGENICALY COOLED AMPLIFIERS


CONSTITUTIVE PROPERTIES

Fo,GHz	1,5	2,3	3,9	4,8	5,9	7,5	8,5	11,2	22,0	30,0	37,0	43,0
Noise temperature, K (in frequency band 20%)	6	7	7	8	9	10	12	15	25	30	35	40

THE BLOCK DIAGRAM OF ULTRA-LOW-NOISE RADIOMETER

      1,2. Directional couplers.
      3. Calibration noise generator.
      4. Communication unit.
      5. Cooled transistor amplifier.
      6. Noise generator of compensation.
      7. Thermostabilization device.
      8. Modulator.
      9. Microcryogenic system.
      10. Amplifier.
      11. Supply unit.
      12. RF filter.
      13. Mixer.
      14. IF amplifier.
      15. IF filter.
      16. Device of thermostabilization.
      17. Block of remote control and diagnostics.