RATAN-600 Radiometer = 1.4 cm
Technical information:
Central frequency
21.65 GHz
Bandwidth
2.5 GHz
Bandpass Filter
20.4 - 22.9 GHz
Front end amplifier
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Physical temperature
15 ë
System noise temperature
77 ë
Realized sensitivity ( = 1 s )
3.5 më
Design
Switching Radiometer
Operating modes
Double - beam switching or
Single - beam mode with a cooled reference
Polarization
No
Feed Horn
Quasi Scalar
Calibration
Noise generator

Simplified block-diagram of the radiometer

  • PF1, PF2 - input feed horns,
  • DC1, DC2 - directional couplers,
  • S1, S2 - latching circulator switches,
  • CI - cooled ferrite isolator,
  • GM - p-i-n diode gain modulator,
  • BPF - band-pass filter,
  • D - square law detector,
  • NG1 - noise generator for calibration,
  • NG2 - balance noise generator,
  • A1- noise power control attenuator,
  • LFA - low frequency amplifier.


Interior of the 15 K cryostat:


Cooled front-end of the 1.4 cm radiometer: