RF Amplifiers in EW (Electronic Warfare) and GNSS Jamming
Global Navigation Satellite Systems (GNSS) have become an integral part of people’s lives in the 21st century. They offer a broad array of uses for the military, scientists, pilots, first responders, and even civilians going about their everyday
lives. Although these signals are commonly used around the world, they are prone to signal jamming and spoofing.
While GNSS jamming and spoofing are illegal in areas that could affect civilian life, these devices are often used for military operations and research. Continue reading to learn more about what GNSS signal jamming (a.k.a. GPS denial) and spoofing are, and the impact RF amplifiers have on GNSS signals.
Why are GNSS Signals so Weak?
GNSS signals operate off satellites that orbit the earth. In the case of the USA’s GNSS, the Global Positioning Systems, or GPS*, there are approximately 24 operational satellites orbiting the earth that transmit a unique signal for GPS devices
to decode. Individual devices receive signals from multiple satellites at once. It is the triangulation of these signals that provides users with a precise location.
The problem is that these signals must travel very far distances—around 22,000 miles from the satellite to the earth’s equator. The farther the signals have to travel, the weaker they are once they reach the receiving devices. This weakness means the receiving electronics must be very sensitive, but that sensitivity leaves GPS signals open to being jammed and spoofed.
*For the purposes of this blog, we will be using GNSS and GPS interchangeably.
What is Signal Jamming?
GNSS signal jamming occurs when a strong electromagnetic field is created by a high-power RF transmission to overload the GNSS receivers until they lose Course Acquisition or Code Access (C/A) lock on their given satellites. The jamming signals (L1 at 1575MHz, L2 at 1228MHz, and L5 at 1176MHz) need to be at the same frequency as the GPS signal, just at a higher power when they reach the receiving device.
To simplify, picture yourself in a conversation with someone in a car. Your voices are the normal GPS signal. The jamming signal would be someone turning the volume on the radio all the way up, drowning out your voices.
What is Signal Spoofing?
GPS signal spoofing is when someone tries to mimic another person’s GNSS signal by learning about the victim’s GPS setup and trying to replicate it. They then make the fake signal stronger than the original, so the receiver picks up on the
fake signal instead of the real one.
Another way to think about it is like this: If you were talking at the same time a perfect recording of your voice was playing, but the recording was louder, how do you distinguish the two? Now imagine those voices were in two different locations. Would you be able to decipher which was real if the only difference between the voices was the volume?
RF Amplifiers in GPS Jamming
Amplifiers in general take the frequency provided by the source and make it stronger to reach a broader area. RF amplifiers work the same way. They are critical for boosting the jamming signal’s output power, overpowering and blocking authentic GNSS signals operating on the same frequency.
GNSS Jamming Applications for Amplifiers in Non-Military Settings
Amplifiers can be used for GNSS jamming in non-military settings, though they are still extremely limited in their use cases. When amplifiers are not used in military settings to block potential signals, they are used for law enforcement in
large events and around prisons.
Amplifiers are kept in large events as protection options against potential IED (improvised explosive device) situations, drone surveillance, and other trackers. Additionally, these amplifiers can be used in prisons to prevent unmediated contact with the outside world, whether that be phone calls or drones dropping contraband into said prison.
Amplifiers in Electronic Warfare
Modern armed forces rely heavily on GNSS for position, navigation, and timing (PNT) across virtually all operations, including troop movements, targeting, communications, and logistics. Because it is used for so many crucial aspects of war
, most DoD sectors use amplifiers for GNSS signal jamming and spoofing, whether that be in the CIA, Army, Air Force, etc.
GPS jamming plays an active role in most modern wars, as they are crucial to disrupting enemies’ positioning and communications. Jamming or spoofing GNSS signals can create vulnerabilities in the offensive capabilities of the adversary. In a GNSS-denied environment, military units may lose situational awareness, the ability to coordinate effectively, and the precision needed for weapons guidance and force synchronization.
How ATEC Can Help You
Advanced Test Equipment Corp rents out a wide range of high-power amplifiers from leading manufacturers such as Empower. Examples of these amplifiers are as follows:
We offer these amplifiers and more to help you meet your R&D and testing needs. For more information on our vast inventory of amplifiers available for rent, visit www.atecorp.com.