Agilent/Keysight 85025E

The Keysight 85025E is a precision coaxial detector engineered for RF and microwave measurements in scalar network analyzer systems. It converts signals from Type-N male to 7mm connectors, enabling accurate power detection across the 10 MHz to 26.5 GHz band. The detector operates in both AC and DC modes: AC detection captures the envelope of modulated microwave signals (e.g., 27.8 kHz modulation), while DC detection measures absolute microwave power levels.

Designed specifically for the Keysight 8757D scalar network analyzer, it reads internal frequency correction factors from an onboard EE PROM for optimized measurement accuracy across frequency.

Technical Specifications

• Frequency Range: 10 MHz to 26.5 GHz


• Nominal Impedance: 50 Ω


• Maximum Input Power: +20 dBm; ±10 VDC


• Return Loss: Maximum 17 dB (10 MHz to 26.5 GHz)


• Frequency Response: ±0.25 dB to ±0.5 dB (10 MHz to 26.5 GHz)


• Detection Modes: AC (modulated signals) and DC (power measurement)


• Transmission Measurement Uncertainty (10 GHz, DUT SWR=1.5, power change <30 dB): 0.73 dB total (Dynamic Accuracy 0.40 dB, Mismatch 0.33 dB)


• Absolute Power Measurement Uncertainty (50 MHz, DUT SWR=1.5, power = 0 dBm): Absolute Power Accuracy 0.40 dB, Frequency Response 0.50 dB, Mismatch 0.10 dB

Key Features

• Dual-mode detection: envelope (AC) and absolute power (DC) measurement


• Internal EE PROM stores frequency-dependent calibration coefficients


• Automatic correction factor retrieval by 8757D analyzer


• Maximum measurement accuracy when paired with 8757D internal power calibrator (Option 002)


• 50 Ω nominal impedance for standard RF/microwave systems

Compatibility & Integration

• Compatible Analyzer: Keysight 8757D Scalar Network Analyzer


• Incompatible Models: Keysight 8756, 8755


• Firmware Requirement: Agilent 8757A firmware revision 2.0 or higher


• Connector Interface: Type-N male to 7mm adapter configuration