Agilent/Keysight U8481A

The Keysight U8481A is a USB thermocouple power sensor that delivers accurate average power measurements from 10 MHz to 18 GHz, with optional DC coupling extending capability down to DC. Featuring power linearity of less than 0.8%, the sensor captures up to 900 readings per second - more than 20 times faster than legacy series instruments. Its wide dynamic range of −35 dBm to +20 dBm accommodates both low-level and moderate-power signals with real-time measurement uncertainty reporting.

Direct USB 2.0 connection to a PC streamlines integration with test automation systems and enables immediate data logging through BenchVue software and standard programming interfaces.

Technical Specifications

• Frequency Range: 10 MHz to 18 GHz (standard); DC to 18 GHz with Option U8481A-200


• Power Measurement Range: −35 dBm to +20 dBm


• Power Linearity: Less than 0.8%


• Measurement Speed: Up to 900 readings per second (free run/fast buffer mode)


• RF Connector: N-Type plug (50 Ω nominal); APC-7 available (Option 001)


• Operating Temperature: 0°C to 55°C


• Interface: USB 2.0, USB-TMC compliant


• Current Draw: Approximately 400 mA (N-Type, 50 Ω)

Key Features

• Real-time measurement uncertainty feature for confidence in results


• S-parameter and gamma correction functions for improved accuracy


• DC voltage/power handling up to 25 dBm average power, 4 V DC, and 15 W peak (2 μs) with Option 200


• Built-in external trigger input (BNC to SMB cable required)


• NIST/NPL traceability with ISO 17025 and ANSI Z540 compliant calibration options available

Typical Applications

• Signal source and network analyzer calibration


• Power reference standards in metrology labs


• EMC testing and compliance measurement


• High-speed power monitoring in RF system design and validation

Compatibility & Integration

• BenchVue software enabled via Power Meter/Sensor Control and Analysis App (BV0007B)


• Programmable through SCPI, Keysight VEE, LabVIEW, and Microsoft Visual Basic


• USB-TMC support ensures compatibility with industry-standard test frameworks