Agilent/Keysight 8485A

The Agilent/Keysight 8485A is a thermocouple power sensor that delivers precise RF power measurements from 50 MHz to 26.5 GHz, with optional extension to 33 GHz. It interfaces with compatible power meters to provide stable, traceable readings across component testing, system integration, and signal monitoring workflows. The thermocouple sensing element combined with internal EEPROM-based calibration factor storage ensures reliable operation in demanding technical environments.

Technical Specifications

• 50 MHz to 26.5 GHz (standard)


• Up to 33 GHz with Option 033 Power Measurement Range


• –70 dBm to +20 dBm


• 1 µW to 100 mW Impedance & Connector


• 50 ohm characteristic impedance


• APC-3.5 mm (male) connector


• Includes Type N to 3.5 mm adapter (HP 8485-60005) for 50 MHz calibration Accuracy & Linearity


• Power accuracy: 0.6 dBm


• Power linearity (N8485A, 25 °C ± 10 °C): ±0.52% (–1 to <+15 dBm), ±0.80% (+15 to +20 dBm)


• Power linearity (U8485A): <0.8% Standing Wave Ratio (SWR)


• Maximum SWR (N8485A, 25 °C ± 10 °C): - 1.33 (10 to 50 MHz) - 1.08 (50 MHz to 100 MHz) - 1.05 (100 MHz to 2 GHz) - 1.14 (2 to 12.4 GHz) - 1.19 (12.4 to 18 GHz) - 1.26 (18 to 26.5 GHz) Calibration


• NIST-traceable calibration with internal factor storage


• EEPROM automatic calibration factor application


• Calibration port compatible with supported power meters

Key Features

• Thermocouple sensing element for broadband RF/microwave measurement


• Low SWR performance across frequency span reduces mismatch uncertainty


• Internal calibration storage eliminates external reference requirements


• Wide dynamic range from micropower to 100 mW levels

Typical Applications

• Component testing and verification


• System integration and RF characterization


• Signal monitoring and source calibration


• Network analyzer and signal source calibration


• Power reference standards


• EMC testing

Compatibility & Integration The 8485A operates with Agilent/Keysight power meters including EPM-441A, EPM-442A, 435B, 436A, 437B, 438A, 70100A, E1416A, E4418A/B, E4419A/B, EPM series, EPM-P series, and N1911A through N1914A models.