The Keysight U8485A is a USB thermocouple power sensor delivering accurate measurements from DC to 33 GHz (with Option 200) or 10 MHz to 33 GHz in standard configuration. Direct USB connectivity to PCs and Keysight instruments eliminates external power requirements and simplifies measurement workflows. The sensor combines thermocouple measurement principles with a -35 dBm to +20 dBm dynamic range, power linearity better than 0.8%, and acquisition rates exceeding 900 readings per second. Measurement uncertainty remains tight across operating temperature with noise floor below 80 nW and drift of ±10 nW. An external trigger input via standard BNC-to-SMB connector enables precise capture of small signals near the noise floor. The U8485A inherits front-end design from legacy Keysight 8480 and N8480 series power sensors while adding contemporary USB integration and improved performance specifications.
Technical Specifications
• Frequency Range: 10 MHz to 33 GHz (standard); DC to 33 GHz (with Option 200)
• Dynamic Range: -35 dBm to +20 dBm
• Measurement Principle: Thermocouple
• Power Linearity: <0.55% from -1 to +15 dBm; 900 readings/second (fast mode)
• Noise Floor: <80 nW
• Zeroing Accuracy: ±25 nW
• Drift: ±10 nW
• Maximum Input Power (HF): +25 dBm average
• Maximum Input Voltage (DC): 4 VDC
• RF Connector: 3.5 mm, 50 Ω
• Dimensions: 136.5 mm (L) × 46 mm (W) × 35.9 mm (H)
• Weight: 0.25 kg
– Key Features
• USB powered — draws all power directly from host port
• External trigger input for signal synchronization and low-level measurement control
• Cable length options: 5 ft (1.5 m) standard; 10 ft (3 m) and 16.4 ft (5 m) available
• DC measurement capability via Option 200
– Typical Applications
• Component power characterization and validation
• Signal source and network analyzer output power monitoring
• System integration and bench-level power assessment
– Compatibility & Integration
Operates with Keysight BenchVue software and the BV0007B Power Meter/Sensor Control and Analysis App at no additional cost. Functions as a standalone accessory for Keysight EPM power meters (N1913B/14B and N1913A/14A) and network analyzers. Integrates with other Keysight instruments for dedicated power measurement without requiring a separate PC.
