HP-Agilent/Keysight R8486D

The R8486D diode waveguide power sensor measures average power over the frequency range 26.5 GHz to 40 GHz and power range -70 to -20 dBm (50 dB dynamic range).

Excellent SWR for reducing mismatch uncertainty
50 MHz calibration port
Accurate calibration and traceability to US National Institute of Standards and Technology (NIST) millimeter-wave sensor calibration
Compatible with EPM (new N1913A/ 14A, E4418B/ 19B), EPM-P (E4416A/ 17A) and P-series (N1911A/ 12A) power meters, plus the E1416A VXI and discontinued 70100A and 43X power meter
Accurate average power measurements over -70 to -20 dBm
Frequency range 26.5 GHz to 40 GHz
Diode power sensing element

The Keysight 11708A 30 dB attenuator is supplied with 8480 series power sensors with the “D” suffix, for calibration with the power meter 0 dBm, 50 MHz reference.
Datasheet