**Let's Learn the Basics**

Posted by
Bliley Technologies on Jun 15, 2016 9:48:18 AM

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Topics: phase noise, satcom, engineering

Posted by
Bliley Technologies on Jun 14, 2016 9:00:00 AM

To begin understanding phase noise, here are some basic definitions of Phase Noise and what is known as Jitter.

## In the simplest terms, phase noise describes the stability of an oscillator in the Frequency Domain while jitter describes stability in the Time Domain.

To build an in-depth understanding of phase noise, we'll use a simple 5 step process. Once you understand the 5 steps, you'll understand what makes phase noise...well... phase noise!

I bet you're wondering how Spectral Density is connected to Phase Noise in the 5 step process. Here's some more details on each step:

**Step 2:** When plotting each spectral density point at varied frequency intervals of your choosing (In this case every 1Hz), you're left with a graph that looks like this:You are now looking at what is known as the **Signal Power Density** (Step 2) of the noise.

Now focus only on the upper sideband of the graph from fstart to fstop called the "Single Side Band". Check out the illustration below:

**Step 3:** We can now refer to the plotted part of the single side band as noise (Anything above the nominal oscillator frequency (Fosc) and not harmonically related can be considered phase noise). The technical term for this part of our graph is **Noise Power Density** (Step 3). We measure noise power density in dBW (LOG(Watts)) at this point because of the large range which we are looking.

So...

...and that's where phase noise comes from! Easy, right?

Here are some common sources of phase noise in crystal oscillators caused by vibrations (jitter).

Phase noise is considered one of the most important aspects of an oscillator's performance. Therefore, it is important to understand an in-depth look at what phase noise is and some of its common causes.

Now that you know all about phase noise and jitter, you'll have an easier time selecting the best output signal type in your oscillators. After all, the consideration of phase noise differs from application to application.

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Topics: phase noise, OCXO, engineering

Posted by
Bliley Technologies on May 30, 2016 7:00:00 AM

Inside of every quartz oscillator is something called a crystal blank. The crystal blank is the resonating element of the oscillator that when subjected to a voltage potential will begin to vibrate and oscillate at it’s "fundamental frequency.” As you can probably imagine, the way that crystal blank is manufactured can have a significant impact on the oscillators performance. One of the most impactful manufacturing steps to crystal, and therefore oscillator performance, is the orientation of the quartz when the crystal blank is cut.

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Topics: crystal aging, crystals, phase noise, OCXO

Posted by
Bliley Technologies on May 19, 2016 10:29:57 AM

Bliley’s Poseidon series OCXO features the world's lowest phase noise performance when subjected to dynamic random vibration conditions. Designed for demanding vibration environments the Acceleration Sensitivity is as low as 0.007 PPB/G for all 3 axis of vibration. For applications requiring superior noise performance out to 1MHz offset, Poseidon is well suited for: Ground Mobile, Airborne, and Shipboard environments.

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Topics: phase noise, aerospace, OCXO