For example: Agilent E4440A or Anritsu 68369
Tektronix
Tektronix 2754P
Programmable Spectrum Analyzer 10kHz to 21GHz expandable to 220GHz
Category: Spectrum Analyzers
Tektronix 2794
RF Spectrum Analyzer, 10 kHz to 21 GHz (325 w/optional mixers)
Category: Spectrum Analyzers