GAJT Anti-Jam Antenna

GAJT™ Dual-Frequency GPS Anti-jam Antenna

View GAJT Video

 

GAJT (pronounced “Gadget”) is the first single unit GPS anti-jam antenna appropriate for use with military land vehicles, networks and timing infrastructure. GAJT nullifies jammers, ensuring satellite signals necessary to compute position and time are always available.

GAJT provides anti-jam performance comparable to much larger systems, but at a significantly lower cost. GAJT is a Commercial Off-the-Shelf (COTS) product, providing short order lead times and quick deployment. It easily integrates into new vehicle platforms or can be retrofitted with GPS receivers and vehicle navigation systems on existing and legacy military fleets.

Features

  • Commercial Of The Shelf (COTS)
  • 7 antenna elements create 6 independent nulls
  • GPS L1 and L2 with an upgrade path for other GNSS constellations
  • M-Code ready (24 MHz bandwidth)

Benefits

  • Immediate availability for urgent operational needs
  • Simple assembly means easy to install or retrofit
  • Compatible with existing GPS receivers and vehicle navigation systems
  • Non-ITAR product to ease export to authorized customers
  • Minimal integration training required

Attributes

General Info

Width/Diameter (mm)
290.00
Height (mm)
120.00
Weight (g)
7500.00

Constellation

GPS

Tracking

Max Num of Frequency
Dual
SBAS
QZSS

Antenna Form Factor

Other

Antenna Mounting

Screw

Performance

LNA Gain (dB)

30

Developed with International Expertise

GAJT was developed by NovAtel and QinetiQ, two world leaders in their respective industries. Manufactured in Canada and incorporating Canadian and UK technology, GAJT only requires Canadian and UK export approval, so exporting to authorized customers in foreign countries is simplified.

With minimal integration training necessary, this externally mounted unit requires only power and a single RF cable. No additional electronics are necessary inside the vehicle.

Variants

How it works

 

Protects Position; Saves Lives

GAJT’s proprietary technology uses a concept similar to that of noise-cancelling headphones; it nullifies the jammers that are trying to overpower the satellite signals that GPS positioning systems use to compute location. GAJT defeats jamming thanks to antenna elements that create up to six independent nulls in the direction of the jammers. With the jammer nullified, your receiver is clear to acquire and track the GPS signals you need to ensure accurate battlefield position.

Without GPS anti-jam technology, a simple 1-watt jammer can overpower GPS signals within a large area, denying a position solution from the victim receiver. GAJT improves the GPS jamming immunity of the connected receiver, significantly decreasing the reach of the jammers, ensuring that positioning capabilities are retained during combat, training or other vehicle based missions.

Without GAJT, operational positioning is lost

With GAJT, operations proceed unobstructed

Successfully tested by both the Canadian and British military, GAJT leverages the proven expertise of two technology leaders known for their products’ performance and reliability. Military personnel can depend on GAJT to help maintain situational awareness, protecting soldier’s lives and improving strategic battlefield performance.

 

Jammers prevent determination of vehicle position and time.

GAJT generates antenna “nulls” to
mitigate jammers

GAJT generates multiple nulls to defeat
multiple jammers

Installation

 

Instant anti-jam protection

The compact, efficient design of the GAJT antenna makes the addition of anti-jam capability to existing and new vehicles easy. GAJT is externally mounted, requiring no additional electronics inside the vehicle—only power and a single RF cable.

Vehicle with typical GPS system and
antenna installed

GAJT requires only power and
existing antenna cable

With minimal vehicle alterations required, operator training is unnecessary because the original GPS unit remains in place.

The self-enclosed GAJT provides an all-in-one solution unlike other anti-jam devices that typically feature more than one component. This results in faster installation, minimizes vehicle downtime and installation training, and makes it easy to integrate or retrofit into existing and legacy fleets.

Big impact in a small package

GAJT is an active antenna based on a 7-element controlled reception pattern antenna and null-forming algorithm. The antenna adapts the reception pattern to reduce the gain in the direction of malicious and accidental jammers. Incorporating NovAtel’s patented 7-element Pinwheel™ antenna, seven independent copies of the GPS L1 and L2 frequencies are acquired from seven different locations within GAJT’s radome. These are then down-converted to intermediate frequency for high-speed digital sampling and processing by QinetiQ’s proprietary null-forming algorithm. This optimizes the power and phasing of the seven independent signals to create a single, high quality output signal. The output is then up-converted to the original GPS frequencies. The clean output signal is delivered through a standard TNC connection, via coaxial cable, to the antenna input port on new or legacy GPS receivers.

About Us

 

NOVATEL INC.: Serving Defense Markets Since 1992

NovAtel is a pioneer in the GPS industry and is the world’s leading original equipment manufacturer (OEM) provider of Global Navigation Satellite System (GNSS) technology. NovAtel receivers, antennas and subsystems are used in a wide range of military applications including unmanned vehicles, vehicle tracking and navigation, and many others that require reliable, precise, continuous positioning. NASA, US and Canadian defense organizations as well as large military system integrators have all relied on the quality of NovAtel technology since 1992.

NovAtel’s augmented systems, including our SPAN™ GPS + Inertial technology, provide continuous attitude (roll, pitch, and yaw) plus position and velocity, even in the most difficult environments where satellite signals may be blocked for short periods of time. With the launch of the new GAJT anti-jam technology, NovAtel ensures troops and commanders relying on GPS positioning for mission success can proceed with confidence.

About QinetiQ PLC

QinetiQ is a leading international provider of technology-based services and solutions to the defense, security and related markets. QinetiQ develops and delivers services and solutions for government organizations, predominantly in the UK and U.S., including defense departments, intelligence services and security agencies. In addition, QinetiQ provides technology insertion and consultancy services to commercial and industrial customers around the world.

www.qinetiq.com

GPS & Jamming

 

GPS technology has revolutionized modern warfare. It is now regularly depended on for accurate positioning, targeting and communications. For information on how GPS and other satellite systems of the Global Navigation Satellite System (GNSS) operate, refer to our book “An Introduction to GNSS: GPS, GLONASS, Galileo and Other Global Navigation Satellite Systems”.

While the value of GPS is unquestionable, the increasing availability of jamming technology is proving problematic. GPS signals are transmitted on published radio frequencies from satellites that orbit 20,000 km above the earth. The GPS transmit levels from the satellites are extremely low power, and are only about 50 x 10-18 W by the time they reach the surface of the Earth. This fundamental weakness makes the signals vulnerable to both accidental and deliberate interference. Although illegal, devices that jam GPS signals are easy to obtain. Simple models that plug into 12-volt car receptacle connectors can be purchased for as little as $30 online and can render GPS systems inoperable for miles around.

Instances of recent GPS jamming include:

Learn more about GPS Jamming: