Agilent / Keysight Q8486D Waveguide Power Sensor

The Keysight Q8486D is a waveguide power sensor designed for precise average power measurement in the Ka band from 33 GHz to 50 GHz. Operating with a diode power sensing element, it delivers a 50 dB dynamic range spanning -70 dBm to -20 dBm (100 pW to 10 µW) with excellent voltage standing wave ratio performance to minimize mismatch uncertainty. The sensor integrates a 50 MHz calibration port and ships with a Keysight 11708A 30 dB attenuator for calibration against a 0 dBm, 50 MHz reference, ensuring traceability to NIST standards for millimeter-wave applications.

Technical Specifications

• Frequency Range: 33 GHz to 50 GHz


• Power Measurement Range: -70 dBm to -20 dBm (100 pW to 10 µW)


• Dynamic Range: 50 dB


• Sensing Element: Diode power sensing element


• Calibration Port Frequency: 50 MHz


• Waveguide Flange: UG-383/U


• SWR: Excellent (reduces mismatch uncertainty)


• Weight: 0.53 lbs (sensor only); 3 lbs (shipping)

Key Features

• Diode-based power sensing for reliable Ka-band measurements


• Integrated 50 MHz calibration port for direct NIST traceability


• Included 30 dB attenuator enables calibration with standard 0 dBm reference signals


• Low-loss waveguide interface minimizes systematic error


• Wide 50 dB dynamic range accommodates sub-microwatt to low-microwatt power levels

Typical Applications

• Ka-band component and amplifier characterization


• Millimeter-wave system power monitoring


• Waveguide-based power measurement and calibration


• High-frequency power verification in military and aerospace systems

Compatibility & Integration The Q8486D integrates with Keysight power meters across multiple product lines: EPM series (N1913A/14A, N1913B/14B, E4418B/19B), EPM-P series (E4416A/17A), P-series (N1911A/12A), E1416A VXI platform, and legacy instruments including the 70100A, 43X, 435A/B, 436A, 437A, and 438A power meters.