1. Protected GPS Directional Antenna Array Dr. P. A. Molchanov, Dr. V.M. Contarino, Dr. O.V. Asmolova

2. Anti-jam GPS Phased Antenna Array NAVSYS designed CRPA NOVATEL designed anti- jam GPS antenna array Stanford’s 7 element controlled reception pattern antenna array Jam resistant GPS antenna designed by Air Force Research Lab.

3. Feedback signal forming null in phased antenna array pattern, but LNA will be damaged or drive to saturation by powerful jamming signals before processing Jammer Planar Phase Array cannot protect GPS against strong Jamm signals

4. Anti-Jam antennas manufacturers and researchers NOVATEL Inc.GAJT (GPS Anti-Jam Technology) Boeing Inc.AGTFT(Air Forcr’s Anti-Jam GPS Technology Flight Test) Honywell Inc.GPS anti-jam technology Raytheon Inc.GPS anti-jam systems Lockheed Martin Inc.G-STAR Mayflower Communications Corp.GPS/A Anti-Jam NAVSYS Inc.CRPA (Controlled Reception Pattern Antenna) Air Force Research Lab.Jam resistant GPS Stanford UniversityCRPA Ohio University, COUNTAnti-Jam Adaptive Antenna Array Price of anti-jam antenna array 25000 USD

5. Any time directional antenna array receiving information from a few satellites independent of direction, tilt, jam source.

6. Second level of protection: Multichannel processor is estimating direction of arrival (DOA) for each receiving channel and comparing with true satellite position from memory. If position wrong, receiving channel will be turned off by switcher. First level of protection: Convex shape. Any time directional antenna array receiving information from a few satellites independent of direction, tilt, jam source. Switching receiving channel off (>40 dB) or limiting signal from directional antenna in jammer direction if jam signal larger than threshold value. Protected Directional Antenna Array

7. Gain of Directional antenna larger than omni-directional antenna 5-25 dB

8. Gain in direction of one satellite decreasing in phase (adaptive) antenna array with increasing number of satellites, and practically not change for directional antenna array Table 1. Beam steering gain on satellites signal Number of elements Gain (dB)Gain of one element (dB) 78.51.21 16120.75 10920.40.187

9. Directional Antenna Array can receive signals from any direction independent of tilt and have advance for small UAS, UGS applications Planar Phase arrays have limited beamwidth and can loss signal when array tilt

10. 8mm 5mm 6mm

11. Anti-jam GPS Directional Antenna Array Advantages: Simplest implementation –many options New nano-materials can probably make a much better performance array Number of antennas vs performance can be adjusted to provide proper protection. Array is easily electronically controlled with gated detector/LNA receivers.

12. Anti-jam GPS Directional Antenna Array Advantages Directional antennas can have higher gain – therefore less sensitive LNAs and less susceptibility to EMI damage. Only antennas turned on are susceptible to damage, jamming or spoofing. Jammer would have to be in the path of the tracked satellites for jamming, spoofing or damaging. Having more than 3 good satellites tracked would allow detection and defeat of a spoofing signal.

13. Application of GPS Directional Antenna Array for Robotic Sensors Navigation GPS Directional Antenna Array

14. Distributed Radar Concept Position of Intruder calculated by measurement time delay and triangulation Transmitter + GPS + DAA Receiver + GPS Antenna Patterns

15. Dipole Antenna Application of Directional Antennas for Aircraft Communications Monopole Antennas

16. Disadvantage of Dipole Antenna Application for Sense and Avoid Systems

17. Directional Anti-jam GPS Antenna Array

18. Anti-jam Directional Antenna Array for Control and Communications