The Keysight (formerly Agilent/HP) 8481A is a thermocouple average power sensor operating from 10 MHz to 18 GHz with a power measurement range of -30 to +20 dBm. It features a Type-N (male) connector and is known for its excellent SWR, reducing mismatch uncertainty. The sensor is compatible with a wide range of legacy and modern power meters including the EPM, EPM-P, P-series, and the classic 43X series.

Specifications

Physical

ParameterValue
Operating Temperature0 to 55 °C

Frequency Specifications

ParameterValue
Frequency Range10 MHz to 18 GHz

Power Specifications

ParameterValue
Power Measurement Range-30 dBm to +20 dBm (1 µW to 100 mW)
Maximum Average Power (Damage Level)300 mW (+24.8 dBm)
Maximum Peak Power (Damage Level)15 W (pulse width ≤ 1 µs)
Maximum Energy per Pulse15 W·µs

Impedance & VSWR

ParameterValue
Nominal Impedance50 Ω
Maximum VSWR (10 MHz to 30 MHz)1.40

Performance

ParameterValue
Sensing ElementThermocouple
Zero Set±50 nW
Zero Drift±15 nW
Measurement Noise110 nW

Compatibility & Interface

ParameterValue
Compatible Power MetersEPM, EPM-P, P-series, E1416A VXI, 70100A, 43X-series
RF Input ConnectorType-N (male)
Sensor Interface ConnectorProprietary Keysight/HP Power Sensor Cable Connector

Environmental

ParameterValue
Storage Temperature-40 to 75 °C

Calibration

ParameterValue
Calibration Reference Frequency50 MHz
Calibration Reference Power1 mW (0 dBm)

Technology

Thermocouple Power Sensor

Applications

RF and Microwave Power Measurement