Who can I contact for spectrum analyzer mixer capabilities above 110 GHz?

For preselected and non-preselected coverage in the bands of 18 GHz to 110 GHz:

Preselected:

For 26.5 GHz to 75 GHz bands, use the 11974 Series preselected mixer from Agilent Technologies

Non-Preselected:

For 18 GHz to 110 GHz bands, use the 11970 Series harmonic mixer from Agilent Technologies.

For 110 GHz to 325 GHz bands, Agilent recommends the following contact:

• Oleson Microwave Labs
  17020 Oak Leaf Drive
  Morgan Hill, CA 95037
  Phone: 408 779-2698
  Fax: 408 778-0491

Link to Oleson Microwave Labs Home Page