Inside Frequency Control

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.

While GPS technology plays an important role in modern navigation, it's not perfect. Although GPS might perform well enough consumer usage, signal jamming or other disruptions present serious threats to military operations. 

Enter assured positioning, navigation, and timing (A-PNT), new technology that enhances traditional GPS timing. Assured PNT uses additional sources to augment GPS and prevent vulnerabilities. Its goal is to ensure that accurate positioning, navigation, and timing (PNT) is always available.

In this blog, we'll review GPS, its flaws, and other PNT systems (like the GNSS) and give you an overview of how assured PNT technology uses other systems to improve effectiveness. 

GPS disciplined oscillators (GPSDO) are some of today's most trusted and accurate sources of timing. These powerful devices (sometimes called GPS clocks) consist of a high-quality stable oscillator and a GPS receiver. The GPSDO works by disciplining (or steering) the oscillator output to a GPS device or GNSS satellite signal via a tracking loop.

The U.S Department of Homeland Security considers 13 of the nation’s 16 critical infrastructure sectors to be ‘critically dependent’ on PNT technology. Also, a loss of PNT would cost the U.S an estimated $10 BILLION a day. Not only do many everyday consumers use PNT & GPS on a daily basis, it's also crucial for military and intelligence operations. Other industries that strongly rely on GPS based PNT include

• Radio communications
• Network synchronization
• Intelligence systems
• Information gathering
• Cruise missiles
• Weapons systems
• Electronic warfare

Building resilience into Global Positioning System (GPS) timing and frequency receivers is crucial in the 21st century. Since the presidential directive on U.S Space-Based Position, Navigation, and Timing (PNT) and Critical Infrastructure Protection (PPD-21), federal agencies have been advancing their efforts when it comes to GPS and Global Navigation Satellite System (GNSS) capabilities. 

Electronic warfare (EW) is a continuous competition between electronic countermeasures (ECM) and electronic counter-countermeasures (ECCM). Electronic warfare systems deploy millions of sensors worldwide on a wide range of platforms such as IR, Acoustic, Radio, and Optic systems, all in the coordinated effort to harness and control the RF (radio frequency) spectrum, the highly contested electronic battlespace.

Raytheon's Next Generation Jammer (NGJ) has been under development now since 2013. In 2016 the US Navy awarded the company a 1 billion dollar engineering and manufacturing development contract for the NGJ system slated to replace the ALQ-99 legacy systems used in the EA-18G electronic attack aircraft.

There is an old pearl of wisdom which claims that necessity is the mother of invention and nowhere is that truer than in the history of warfare, and especially electronic warfare. New military technology is always followed by innovative countermeasures developed specifically to defend against the new threat. In the case of electronic warfare, defensive measures quickly evolved into new offensive and intelligence gathering technologies.