The measurement of thermal radiation at microwave frequencies.

  title={The measurement of thermal radiation at microwave frequencies.},
  author={Robert H. Dicke},
  journal={The Review of scientific instruments},
  • R. Dicke
  • Published 1 July 1946
  • Physics
  • The Review of scientific instruments
The connection between Johnson noise and blackbody radiation is discussed, using a simple thermodynamic model. A microwave radiometer is described together with its theory of operation. The experimentally measured root mean square fluctuation of the output meter of a microwave radiometer (0.4°C) compares favorably with a theoretical value of 0.46°C. With an r-f band width of 16 mc/sec., the 0.4°C corresponds to a minimum detectable power of 10-16 watt. The method of calibrating using a variable… 

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