Keysight 8480 Series RF Power Sensors
6 models with full specifications from Keysight Technologies (Agilent HP).
The Keysight Technologies (formerly Agilent / HP) 8480 Series is a family of thermocouple and diode RF power sensors designed for average power measurements. These sensors interface with compatible legacy and modern power meters—such as the EPM, EPM-P, and P-series—to address diverse RF and microwave measurement tasks. The series provides options spanning from 100 kHz to 26.5 GHz, with varying power ranges, impedance levels, and connection types to suit specific test setups. This guide outlines the key differences between the thermocouple models, high-power models, high-sensitivity diode models, and the 75-ohm option within the family.
- Sensor Technologies
- Thermocouple and Diode
- Frequency Range
- 100 kHz to 26.5 GHz
- Power Range
- -70 dBm to +44 dBm
- Impedance Options
- 50 Ω and 75 Ω
Models in this series
| Model | Type | Frequency Range | Nominal Impedance | Operating Temperature |
|---|---|---|---|---|
| 8485D | Power Sensors | 50 MHz to 26.5 GHz | 50 Ω | 0 to 55 °C |
| 8481A | Power Sensors | 10 MHz to 18 GHz | 50 Ω | 0 to 55 °C |
| 8481B | Power Sensors | 10 MHz to 18 GHz | 50 Ω | 0 to 55 °C |
| 8485A | Power Sensors | 50 MHz to 26.5 GHz | 50 Ω | 0 to 55 °C |
| 8484A | Power Sensors | 10 MHz to 18 GHz | 50 ohms | 0 to 55 °C |
| 8483A | Power Sensors | 100 kHz to 2 GHz | 75 Ω | 0 to 55 °C |
Thermocouple vs. Diode Sensing Elements
The 8480 Series utilizes two distinct sensing technologies depending on the required measurement range. Thermocouple sensors like the 8481A, 8481B, 8485A, and 8483A offer an average power measurement range typically starting at -30 dBm up to +20 dBm (or up to +44 dBm with attenuation). These thermocouple sensors are valued for minimizing mismatch uncertainty.
For low-level signal measurements, high-sensitivity diode sensors like the 8484A and 8485D extend the measurement range down to -70 dBm, with an upper power limit of -20 dBm. These diode sensors are ideal for low-power applications but have lower damage thresholds, with a maximum average power rating of 100 mW (+20 dBm) for the 8485D and 200 mW (+23 dBm) for the 8484A.
Frequency and Connector Configurations
Frequency coverage and RF input connectors vary across the series to match different application environments:
- 8481A: Covers 10 MHz to 18 GHz with a Type-N (male) 50 Ω connector.
- 8481B: Designed for high-power applications from 10 MHz to 18 GHz. It features an integrated 30 dB attenuator to measure power levels from 0 dBm to +44 dBm (1 mW to 25 W).
- 8485A and 8485D: These models extend coverage up to microwave frequencies, from 50 MHz to 26.5 GHz, utilizing an APC-3.5 mm (male) connector.
- 8483A: A specialty sensor designed for 75 Ω impedance systems. It covers 100 kHz to 2 GHz and features a Type-N (75 Ω) male input connector.
Host Compatibility and Calibration
Most sensors in the family, including the 8481A, 8485A, and 8483A, are compatible with standard benchtop meters such as the EPM (E4418A/B, E4419A/B), EPM-P (E4416A, E4417A), P-series (N1911A, N1912A), and legacy meters like the 43X-series. Connection is established via proprietary multi-pin sensor cables, such as the 11730A cable.
Calibration factors for older models like the 8481B are printed on the label for manual entry because they do not support internal EEPROM tables. For reference calibration of the highly sensitive 8485D diode sensor, the model includes a 11708A 30 dB attenuator to facilitate 0 dBm, 50 MHz reference calibration.
Frequently asked questions
- Which model is suitable for 75-ohm cable TV or telecommunications testing?
- The **8483A** is specifically configured with a 75 Ω impedance and a Type-N (75 Ω) male RF input connector, operating from 100 kHz to 2 GHz.
- How does the high-power 8481B sensor handle calibration data?
- The **8481B** does not support internal EEPROM calibration tables. Calibration factors are printed on the sensor's label and must be entered manually into the host power meter.
- What accessory is required to calibrate the 8485D diode sensor?
- The **8485D** includes the 11708A 30 dB attenuator, which is required to perform reference calibration at 0 dBm using a 50 MHz calibration source.