The Rohde & Schwarz NRVS mainframe is designed to read various probe heads from DC-40GHz.
Probe heads are found under item numbers:
693 - URV5-Z4 Insertion unit 100kHz to 3GHz,
694 - NRV-Z53 Thermal Probe DC-18GHz, inc. integral 20dB attenuator or
695 - NRV-Z51 Thermal Probe DC-18GHz. External attenuator may be required.
Typical applications are reading forward powers via DDCs on radiated & conducted immunity systems.