Phase reference standard

  • Precision calibration phase reference standard for the PNA-X nonlinear vector network analyzer
  • Flat amplitude and phase
  • NIST referenced phase calibration
  • Sine to square wave converter provided as standard accessory ensures the comb generator functions at its optimum level for output frequencies above 26.5 GHz.
  • Combined with Keysight Signal Optimizer software (K3101A) for wideband calibration of signal analyzers and oscilloscopes.


  • Output frequency:10 MHz to 50 GHz
  • Input frequency:10 MHz to 6 GHz
  • 1, 2, 4, 8 or 16 divide ratio

USB Interface


  • Rugged connectors
  • High repeatability throughout multiple connects and disconnects
  • Long operating life

Industry-1st phase calibration standard comb generator for precision nonlinear measurements

The Keysight Technologies, Inc. U9391F comb generators were developed to provide precision phase calibration, for non-linear measurements using the PNA-X nonlinear vector network analyser (NVNA), referenced to the National Institute of Standards and Technology (NIST) standard. Additionally, the comb generators can be used to calibrate PNA and PNA-X network analyzers for phase and delay measurements of frequency converters without requiring reference or calibration mixers.

Keysight’s new patented comb generator offers a customer selectable USB controlled frequency divider which allows for broad range of input signal frequencies from 10 MHz to 50 GHz and small minimum tone spacing of 10 MHz. The input power and fundamental frequency have lower sensitivity than other comb generators. So you can calibrate the comb generator at a single input power level and frequency and then successfully apply the calibration across a wide range of input powers and fundamental frequencies.

When driven with a sine wave input of less than 100 MHz, (e.g. when connected to the 10 MHz reference of a PNA or PNA-X), the U9391-60009 sine-to-square-wave converter is needed to ensure the comb generator produces optimum power levels across the entire frequency range. Therefore, U9391-60009 is included as a standard accessory for U9391C/F/G.

U9391F Comb Generator

Interested in a U9391F?

Want help or have questions?