For example: Agilent E4440A or Anritsu 68369
Microwave Mixers
Keysight / Agilent 11970K
HP Agilent 11970K Harmonic Mixer 18.0- 26.5 GHz
Manufacturer: Keysight / Agilent
Keysight / Agilent 5086-7982
Agilent Low Band Microwave Mixer Assembly
Manufacturer: Keysight / Agilent