Ultrastable Microwave Generator



Advanced Features and Benefits

  • Compact and complete solution comprising an ultrastable laser and an optical frequency comb
  • Fully remotely controllable
  • Lowest phase noise on the market in this form factor
  • Optional 1 PPS, 10/100 MHz outputs

    System schematic UMS Mini rev01
 Phase noise (absolute*, dBc Hz-1)   Fractional frequency stability (absolute*)
  10 MHz
100 MHz 10 GHz   10 MHz 100 MHz 10 GHz
Offset frequency (Hz)       Averaging time (s)      
1 -135 -125 -80 0.1 <5E-14 <5E-14  <5E-15
10 -145 -135 -100 1 <5E-14  <5E-14  <5E-15
100 -155 -145 -120 10 <1E-13 <1E-13 <2E-14 
1k -165 -150 -140 100 <5E-13 <5E-13 <2E-13
10k -165 -155 -160 1000 <5E-12 <5E-12 <2E-12
100k <-165 -155 <-160 >10000 <5E-11 <5E-11 <2E-11
1M <-165 -155 <-160        
System can be equipped with GPS receiver for long-term steering. De-drift function can be configured for handover at the appropriate time to a more stable reference.
*Inquire for residual.



Photonic microwave technology represents a paradigm shift in microwave signal synthesis. Introducing Menlo Systems’ Ultrastable Microwave Systems, we present a groundbreaking advancement in microwave technology, for the synthesis of microhertz-level linewidth signals. Currently, the most established technology for the synthesis of stable microwave signals is based on up-multiplication of RF signals from oven-controlled crystal oscillators (OCXOs). This method leads to unavoidable and detrimental quadratic upscaling of phase noise. Our systems are the first commercially available photonic microwave sources that utilize the phase-coherent division of high-fidelity optical signals into the microwave domain. By employing this innovative approach, we can drastically reduce optical phase noise to levels that were previously considered physically impossible with multiplied OCXOs or room-temperature Sapphire oscillators.

The UMS-Mini is the microwave frequency source with the lowest phase noise on the market. In a compact 200-liter volume, the rack mountable system can be configured to provide multiple output frequencies from the RF to up to 20 GHz (higher on custom request). It includes a fully autonomous ultra-stable laser and a frequency comb. The system is the result of years of fine engineering.1, 2, 3


1) Xie, X. et al. Photonic microwave signals with zeptosecond-level absolute timing noise. Nature Photonics 11, 44–47 (2016).

2) Giunta, M. et al. Compact and ultrastable photonic microwave oscillator. Optics Letters 45, 1140 (2020).

3) Zobel, J. W. et al. Comparison of Optical Frequency Comb and Sapphire Loaded Cavity Microwave Oscillators. IEEE Photonics Technology Letters 31, 1323–1326 (2019).

UMS Mini plot under description

 Measurement instrument-limited phase noise trace for a 10 GHz carrier signal.

Menlo Expert Ben Sprenger 2019
Dr. Benjamin Sprenger
Your direct line to our expert

Data sheets

Ordering information

  • Product Code
  • UMS-Mini

+49 89 189166 0

Menlo Systems, Inc.
+1 973 300 4490

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