What is a MOCXO | Multiplied OCXO Working & Manufacturers

MOCXO stands for Multiplied Oven Controlled Crystal Oscillator. To understand what it does, we first need to look at the challenge engineers face when trying to generate very high frequency electronic signals.

Problem with High Frequencies:

At the heart of a high quality oscillator is a quartz crystal. To make a crystal vibrate at a higher frequency naturally (its “fundamental” mode), it must be sliced extremely thin. However, there is a physical limit to this. Once you try to manufacture crystals for frequencies much higher than 100 MHz, the quartz becomes so paper thin that it is fragile, difficult to manufacture and prone to poor performance.

Yet, modern technologies like radar and satellite communications require clock signals in the hundreds of Megahertz (MHz) or even Gigahertz (GHz).

Solution by MOCXO:

A Multiplied OCXO solves this physical limitation by combining two distinct stages into one device as follows:

1. Foundation (OCXO): It starts with a robust, lower frequency quartz crystal (often 10 MHz or 100 MHz) placed inside a tiny, heated chamber called an “oven.” This oven keeps the crystal at a constant, optimal temperature, delivering absolute frequency stability and incredibly “clean” signals (ultra-low phase noise) immune to outside weather or environmental changes.

2. Multiplier: The pure, low frequency signal from the OCXO is fed into a specialized internal electronic circuit known as a frequency multiplier (often utilizing harmonic diode multipliers or specialized low noise Phase-Locked Loops). This circuit multiplies the baseline frequency up to the desired high-frequency output (e.g., from 100 MHz up to 1 GHz).

• Result: By using a MOCXO, engineers get the best of both worlds. They achieve the high frequency output required for microwave and RF systems, while inheriting the ultra-low phase noise and flawless temperature stability of the lower frequency “ovenized” crystal.

Common Applications of MOCXOs

Because they provide exceptionally clean, high frequency signals with virtually zero jitter or noise, MOCXOs are highly specialized and typically used in:

• Radar Systems: Where clean signals are required to detect small, distant moving objects.
• Satellite Communications (SATCOM): For stable data transmission between Earth and orbit.
• Test and Measurement: Inside high end spectrum analyzers and signal generators.
• Deep Space Exploration & Military Aerospace: Where rugged, ultra-stable, high frequency timing is mission critical.

Prominent Manufacturers of MOCXOs

Manufacturing MOCXOs is a complex art that requires deep expertise in both quartz resonator physics and high frequency RF (Radio Frequency) circuit design.

Company	Products/Features
Abracon / NEL Frequency Controls	NEL Frequency Controls is a legendary name in the ultra-low phase noise timing market. Following its acquisition by Abracon, NEL’s specialized portfolio including top-tier Multiplied OCXO is now distributed under the Abracon umbrella.
Quantic Wenzel (formerly Wenzel Associates)	Based in Texas, Wenzel is arguably one of the most famous manufacturers of ultra-low phase noise oscillators in the world. Their multiplied crystal oscillators are considered the gold standard for radar, military, and deep space applications where signal purity cannot be compromised.
Microchip Technology (formerly Vectron International)	Microchip’s timing and synchronization division (built upon their acquisition of Vectron and Symmetricom) offers a vast array of high end frequency control devices.
KVG Quartz Crystal Technology	A premier German manufacturer, KVG specializes in high precision timing components. They produce high frequency, oven controlled multiplied oscillators tailored for European aerospace, telecommunications, and advanced instrumentation markets.
Rakon	It is a global leader in frequency control, particularly for space and telecommunications. While heavily invested in standard OCXOs, they also develop high-frequency, low-noise oscillator solutions (including multiplied designs) for advanced 5G networks, satellite payloads, and synthetic aperture radar (SAR) systems.

Oven-Controlled Crystal Oscillators (OCXO)

Explore ultra stable frequency generation using temperature controlled ovens, crystal cuts, and performance metrics.

• OCXO Basics, Types, and Crystal Cut Comparisons
• Understanding Oven-Controlled Crystal Oscillators
• OCXO SC-Cut Crystal Oscillator: Advantages & Disadvantages
• OCXO PPM vs PPB vs PPS Metrics
• OCXO vs VCXO vs TCXO vs DCXO Comparison
• OCXO vs OCSO Differences
• OCXO vs Rubidium Oscillators
• Low Phase Noise 10 MHz OCXO

Continue Learning Oscillator Fundamentals & Types

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• Voltage Controlled Oscillators (VCOs)
• NE 566 VCO and its application in PLL Design
• Numerically Controlled Oscillator (NCO) and its use in DDS Design
• Understanding YIG Oscillators
• Backward Wave Oscillators (BWO): Advantages & Disadvantages

Compare Oscillator types - OCXO, Crystal, MEMS

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• Crystal vs Resonator Differences
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• Mechanical vs Electrical Oscillators