Active Hydrogen Maser MHM-2020 and Auxiliary Output Generator AOG-110

Auxiliary Output Generator AOG 110

Product Information

Active Hydrogen Maser MHM-2020

Extreme Low Phase Noise and Frequency Stability for Precise Timekeeping and Metrology Applications

Expanding upon the heritage of the world’s most widely installed active Hydrogen Maser, the Microchip MHM-2020 has enhanced the unique Auto-Tune design of the MHM-2010 by re-engineering the electronics and software to attain even better stability for precise timekeeping and metrology applications.

Capable of achieving <3 × 10-16 daily drift rates along with improved environmental stability, the MHM-2020 has been designed for applications requiring extreme frequency stability and low phase noise.

Designed, manufactured and tested in the USA with an eye toward long service deployments, 95% of Masers built at Microchip’s dedicated Maser facility since 1999 are still in operation. Each MHM-2020 is manufactured to meet stringent quality standards and undergoes extensive performance verification testing, prior to deployment.

Auto-Tune with Drift Compensation

The MHM-2020 incorporates an automatic frequency control system to maintain the resonant cavity at a constant frequency relative to the hydrogen emission line. This technique enables the Maser to deliver long-term stability that is only attributed to the most stable cesium atomic standards.
Now, by pairing this technology with the new integrated Drift Compensation software, daily aging rates of <3 × 10-16 can be consistently achieved with the MHM-2020.

Improved Environmental Sensitivity

The Maser is designed to withstand variable voltage, temperature, and magnetic field environments. By carefully selecting electronics and controlling the manufacturing process, each MHM-2020 is designed to achieve a Temperature and Magnetic Field sensitivity of <8 × 10-15/ºC and <2 × 10-14/Gauss, respectively.


The MHM-2020 provides multiple 5, 10, and 100 MHz outputs and 1PPS. Multiple configurations can be ordered to optimise for varied applications.

Low Phase Noise Output Option

The MHM-2020 can be factory configured with low phase noise outputs that enable higher resolution measurements in VLBI applications.

Upgrade your existing Maser

We have ensured that the current industry leading MHM-2010 Maser deployed in the field can be upgraded to the new MHM-2020 depending on the age of the unit. Contact us for details.

Lifetime cost of ownership for active masers is a critical consideration. The MHM-2020 is designed for long life and low maintenance. The hydrogen supply is adequate for over 20 years of operation. An efficient hydrogen state selector minimizes the load on ion pumps (< 0.01 mole per year), and the pumps themselves are designed for greater than 20-year life at nominal hydrogen flux. The TeflonTM bulb coating virtually eliminates any re-coating requirement and has a demonstrated life of over 20 years. Should it be required, the MHM-2020 is designed for on-site module replacement.

Auxiliary Output Generator AOG-110

Microchip’s Auxiliary Output Generator, designated the AOG-110, solves performance and capability issues associated with the use of high stability frequency standards.

Until now, intermediate offset generators that extended a standards frequency range without a performance sacrifice were difficult or impractical to obtain. Microchip’s AOG-110 is now available with a 5 MHz output, programmable over a broad frequency range with extremely high resolution and precise phase control at an economical price.

Available on three buffer-isolated output ports, the 5 MHz output features a high-performance crystal oscillator phase-locked to the external standard’s output reference and employs heterodyne techniques developed for Microchip’s Atomic Hydrogen Maser. Internally the 5 MHz is used to develop one pulse per second (1PPS) which is available as an output. The 1PPS output can be synchronised to an external 1PPS reference by the AOG’s operator controls.

The Chronos difference

Contact our team for specialist advice, support and further information.

Key Features

  • Telemetry monitoring via touch screen and secure Ethernet
  • Dedicated keypad or USB/serial port (secure) allow flexibility in instrument control
  • Drift compensation mode enabling drift as low as <3 x 10-16 /day (typical, after 3 months)
  • Low hydrogen usage for extended maintenance-free operation and demonstrated lifetime of greater than 20 years
  • Internal Time-of-Day clock for internal data time stamping
  • 1PPS synchronisation option for precise calibration to GNSS
  • Multiple 1PPS and RF output options (5, 10 or 100 MHz)
  • Low phase noise option
  • Battery back-up
  • CE compliant