The Agilent/Keysight N8481B is a thermocouple power sensor that delivers precise RF and microwave power measurements across 10 MHz to 18 GHz. Built around a thermocouple sensing element, this sensor achieves 1% accuracy and exhibits excellent linearity characteristics – ±0.52% from +29 dBm to <+39 dBm, and ±1.66% from +39 dBm to +44 dBm. The N8481B minimizes mismatch uncertainty through low SWR performance (1.09 to 1.23 depending on frequency), reducing overall measurement error in demanding test environments.
Technical Specifications
• Frequency Range: 10 MHz to 18 GHz
• Power Measurement Range: −5 dBm to +44 dBm (STD option); 0 dBm to +44 dBm (CFT option)
• Accuracy: 1%
• Linearity: ±0.52% (+29 dBm to <+39 dBm); ±1.66% (+39 dBm to +44 dBm)
• Noise Floor: Maximum 114 μW
• Standing Wave Ratio (SWR): 1.09–1.23 across frequency range; 1.40 typical at 10–30 MHz
• RF Connector: Type N (male)
• Sensing Element: Thermocouple
• Calibration: Automatic readout from EEPROM with NIST traceability
• Dimensions: 83 mm (W) × 114 mm (H) × 283 mm (L)
• Weight: 0.684 kg – Key Features • Automatic calibration data and correction factor readout from internal EEPROM eliminates manual entry errors
• Wide dynamic range accommodates both low-level and high-power RF signals
• Exceptional frequency coverage from 10 MHz into the Ku band (18 GHz)
• Low SWR design reduces mismatch uncertainty and improves absolute accuracy – Typical Applications • Power amplifier characterization and validation
• RF transmitter output power verification
• Network analyzer source power monitoring
• Microwave subsystem power budget analysis – Compatibility & Integration The N8481B integrates with Keysight EPM Series (N1913/14A, E4418/19B), EPM-P Series (E4416/17A), P-Series (N1911/12A), E1416A (VXI), and 70100A power meters. The N8481B-CFT option provides SCPI code compatibility with the 8480A series and is not compatible with discontinued 43x series power meters or the N8262A.
