Inside Frequency Control

Temperature compensated crystal oscillators (TCXOs) are widely used in applications where accurate frequency sources are needed. Because they're less expensive and smaller than oven controlled crystal oscillators (OCXOs), they offer an ideal solution for many portable units that require a reasonably accurate source.

In this blog, we'll review several performance qualities of TCXOs, as well as four common types. 

You've probably heard of ultra-stable oscillators, but what are they good for? Just by the name, you can probably tell they're great for maintaining frequency stability in applications. But what specific applications require very high stability to perform optimally? 

In this blog, we'll discuss the top four applications for ultra-stable oven controlled crystal oscillators (OCXOs).

To make the long journey to earth's orbit or beyond, spacecrafts must be designed to have very precise functionality. Even simple vibrations during pre-launch transportation and powered flight can interfere with the spacecraft’s functionality. These simple vibrations come from many different sources and can inhibit the spacecraft from reaching its full potential.

Spacecraft engineers must also be concerned about very small vibrations, known as micro-vibrations, from a spacecraft’s own moving parts as it operates in orbit. Micro-vibrations are typically sinusoidal with the chance of some integer harmonics and random vibration being present.

In this blog, we'll discuss four of the most common sources of vibration and micro-vibration in satellites and spacecrafts, and how you can reduce or prevent them in your application. 

Swept quartz crystals are necessary in timing applications that require radiation resistance, but it's important to understand how they work and when you should use them. 

In this blog, we'll review what swept quartz crystals are, how they're manufactured, their common applications, and a common misconception about their benefits.

The process of buying crystal oscillators can be a headache if you don't know what to expect. But learning the basics of how to procure frequency control devices can help you plan accordingly and reduce your frustration. 

There are three main things you should know about crystal oscillators and frequency control devices when ordering them:

1. They have long lead times
2. They typically have a long shelf life
3. They have large purchased lot sizes

Let's dive a little deeper into each of these to give you a better idea of how they'll impact your purchasing strategy. We'll keep this blog short and to the point, but if you want to learn more, we've included links to our more in-depth articles on each topic.

When it comes to NTP stratum levels and minimum performance requirements for digital network synchronization, there's definitely a lot to know. A standard first released in 1987 entitled "Synchronization Interface Standards for Digital Networks" from the American National Standards Institute (ANSI) lays out all the official information and requirements. 

With the advances of RF technology over the last many years, most modern spectrum analyzers can now automatically detect changes in phase noise levels (mostly of sine wave signals) measured in units of dBc or rads.

But it’s always a good idea for RF engineers to understand how modern spectrum analyzers measure integrated phase deviation. Or better yet, for them to understand how to optimize a spectrum analyzer’s measurements even further. Believe it or not, but many spectrum analyzer readings of phase noise can be significantly off.

Measuring phase noise deviations is easier than it sounds. All you really have to do is learn how to determine the Root Mean Square (RMS). This is done by calculating the ratio of power from the single-sideband (SSB) phase noise to the carrier.

Here’s the scary thing…

Even if you sit for hours upon hours trying to set a precise initial frequency of an oscillator, it’s still going to drift and the oscillator will not be able maintain that frequency over the full course of its use. In this post, you’ll learn the many sources of frequency instability and why an ultra-stable OCXO may be the fix-all solution.

The #1 Most Critical Factor in High-End Radar & Communication Systems: Low Phase Noise

Phase noise, phase noise, phase noise.

If you’re involved with the design and implementation of communication systems, you most likely hear the term “phase noise” all the time (maybe more times than you’d like). 

There’s a good reason for all this phase noise chat. It’s one of the key factors that determines the overall success or failure of your radar or communications application. It’s even more important in intense environments where strong vibration or g-force is a concern.

Why is maintaining low phase noise such a concern in these applications and environments? And how can you solve the problems associated with the effects of phase noise? By the end of this article, you'll know why and how you should decrease phase noise in your applications.

The harsh truth is, selecting the wrong quartz crystal oscillator can quickly kill any design. With the wide variety of options and specs available on the market today, selecting the perfect crystal oscillator for your design can be a difficult and time-consuming task.