Agilent/Keysight 8481A

The Agilent/Keysight 8481A is a thermocouple power sensor engineered for true average power measurements across RF and microwave frequencies. It delivers precise, stable performance from 10 MHz to 18 GHz, covering power levels from –30 dBm to +20 dBm (1 µW to 100 mW). The sensor meets demanding requirements in design, manufacturing, and metrology applications where measurement accuracy and repeatability are critical.

Technical Specifications

• Frequency Range: 10 MHz to 18 GHz


• Power Range: –30 dBm to +20 dBm (1 µW to 100 mW)


• Maximum Average Power: 300 mW


• Maximum Peak Power: 15 W


• Maximum Energy Per Pulse: 30 µJ


• Impedance: 50 ohms


• Connector: Type-N (male)


• Standing Wave Ratio (SWR): ≤1.10 (10 MHz–2 GHz), ≤1.18 (2–12.4 GHz), ≤1.28 (12.4–18 GHz)


• Sensing Element: Thermocouple


• Measurement Linearity: ±4% at +35 dBm to +44 dBm for 25 W sensors


• Physical Dimensions: 30 mm × 38 mm × 105 mm


• Weight: 0.2 kg

Key Features

• Calibration factor data stored on device label; automatically read by EEPROM-capable power meters


• Low SWR across the operating frequency band reduces mismatch uncertainty


• Handles both CW and complex modulated signals


• Compact form factor for bench and integrated measurement systems


• Operating environment: 0° to 55°C, <95% relative humidity, <4,572 meters altitude

Compatibility & Integration The 8481A connects to Keysight power meter families including the EPM Series (E4418B, E4419B), EPM-P Series (E4416A, E4417A), P-Series (N1911A, N1912A, N1913A, N1914A), and VXI (E1416A). Legacy compatibility with discontinued 435/436/437/438 series instruments is supported. Safety Note: Ground the instrument and power meter before sensor connection. Do not exceed specified maximum power and energy levels. Avoid applying torque to the RF connector body during mating.