Browsing Tag

crystal oscillators

15 posts

The MCXO Is Finally Ready for Space

The latest advances in radiation-hardened digital components have enabled the development of MCXOs that, for the first time, can replace larger, high-power-consuming OCXOs in low-earth orbit (LEO) New Space applications Introduction The last post in this series explored the benefits of microcomputer-compensated crystal oscillators (MCXOs) when compared to (oven-controlled) OCXOs. This post introduces the first MCXO that combines clever engineering design with rad-hardened digital components to qualify for New Space applications. Developing Space-Qualified MCXOs When developing MCXOs in the early 2000s, the space- and rad hard-level digital components needed were very expensive, which meant an MCXO space-level product would sell…

Comparing OCXOs to MCXOs

Oven-controlled (OCXO) and microprocessor-controlled (MCXO) crystal oscillators each provide exceptional frequency stability over a wide temperature range, using very different approaches. Introduction This post will describe the technology behind OCXOs and MCXOs and delve into the Size, Weight and Power (SWaP) benefits provided by MCXOs. The next article in this series will introduce the first space-qualified MCXO for low-earth orbit (New Space) applications. Crystal Oscillator Stability All crystal oscillators are based on the very stable frequency vibrations of a piezoelectric quartz crystal resonator. Usually, the crystals and their associated circuitry are carefully designed and crafted so that the quartz crystal…

Crystal Oscillators 101

Quartz is relatively abundant in nature and easy to grow in a very pure form. What sets it apart from other piezoelectric crystals is that it can be made to vibrate in very controlled and stable ways. Thus, a properly fashioned quartz resonator can act as an ultra-stable mechanical frequency source that can be coupled to an electronic oscillator circuit.

Does anybody really know what time it is? (Part 2)

Quantum physics took the mysteries of time to a whole other level. Is time continuous or discrete? Is there a minimum size of time duration, a sort of quantum of time? Is time fundamental or is it an emergent phenomenon, or is it an illusion? Many scientists now think that time is not fundamental but that it emerges out of nothingness. Of course, nothingness itself is being redefined. Completely empty space is now thought to be a quantum foam, with virtual particles popping into and out of existence randomly and continuously. When these virtual particles happen to interact with each…

Does anybody really know what time it is? (Part 1)

Precise time keeping is of the utmost importance in science and technology and has been since the beginning of recorded time. Yet no one really knows what time is. If you look up the word “time” in a good dictionary you will see one of the longest entries, with dozens of definitions. St. Augustine, in 400 AD, said “What, then, is time? If no one asks me, I know; if I wish to explain to him who asks, I know not.” Time is what a clock measures. The first clocks were natural phenomena, like the sun rising and setting and…