For example: Agilent E4440A or Anritsu 68369
Noisecom Noise [Source/Figure Meter]
Noisecom NC346A Precision
0.01 GHz - 18.0 GHz Broadbrand Calibrated Noise Source
Manufacturer: Noisecom
Noisecom NC346B Precision
0.01 GHz - 18.0 GHz Broadbrand Calibrated Noise Source
Manufacturer: Noisecom