Active Hydrogen Maser

Active Hydrogen Maser

Active Hydrogen Maser Overview

An active hydrogen maser, also know as hydrogen frequency standard, is a specific type of maser used as a precision frequency reference. Its technology is based on the properties of the hydrogen atom.

How does it work?

A hydrogen maser is the most elaborate commercially available frequency standard dedicated to space applications.

The hydrogen maser is specifically designed to create an elaborated chemical reaction around hydrogen atoms in order to get a microwave signal locked to the resonance frequency of the hydrogen atom that will keep on emitting as long as the full system is fed with new atoms.

The active hydrogen maser process is more complex but has a better short-term and long-term frequency. In this configuration, the microwave cavity (or resonant cavity), that hydrogen atoms have to reach to be transformed by an elaborated chemical reaction, is specifically designed to oscillates by itself which requires a higher hydrogen atom density and a higher quality factor for the cavity.


An active hydrogen maser is typically used in the following applications:
  • Primary frequency reference sources
  • VLBI (Very Long Baseline Interferometry) systems
  • Deep space tracking & navigational systems
  • Timekeeping & precision time scales
  • GPS/GNSS satellite control, monitoring & geodetic systems

Did you know?

The word maser is an acronym that stands for Microwave Amplification by Stimulated Emmission of Radiation.

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