Design of smart antenna array for interference suppression in GPS

Download
index.pdf
2016
Dabak, Ömer Can
Show full item record
467
views
519
downloads
GPS jammers add excessive noise to received low power GPS signals and have capability to weaken or completely destroy the positioning performance of GPS receivers. The most popular technique to overcome GPS jamming problem is suppression of jammers by using array signal processing techniques. In this thesis, a GPS anti-jamming system is constructed by designing an active antenna array and implementing adaptive beamforming techniques. This thesis mainly include the design of four element active circularly polarized microstrip antenna array, implementation of beamforming techniques and presentation of experimental results obtained from the constructed GPS anti-jamming system. In active antenna array design, circularly polarized operation of the array element is achieved through nearly square microstrip patch antenna structure. After verification of the design by comparing simulation and measurement results, four element planar array is designed and manufactured. Then, four channel LNA card design and production is performed in order to obtain a compact active antenna array. All electromagnetic simulation and parametric analysis of the antennas are performed in electromagnetic simulation tool CST Microwave Studio. In beamforming section, two main beamforming methods that are Capon beamforming and null steering are studied with theory and simulation results obtained from the code developed in MATLAB environment. The jammer suppression success of the constructed system is demonstrated by scenarios that include real satellites and a continuous wave jammer source.
Radio frequency microelectromechanical systems., Microelectromechanical systems., Antennas (Electronics).
http://etd.lib.metu.edu.tr/upload/12620150/index.pdf
https://hdl.handle.net/11511/25756
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Interference Suppression in a GPS Receiver with 4 Element Array Design and Implementation of Beamforming Algorithms
Dabak, Omer Can; Erdem, Fatih; Sonmez, Tolga; Alatan, Lale; Koç, Seyit Sencer (2016-04-14)
Global Positioning System (GPS) jammers add excessive noise to the received low power GPS signals and have capability to either weaken or completely destroy the positioning performance of GPS receivers for both civilian and military users. Researchers are actively working to develop GPS receiver systems resistant to interference sources. Our aim is to develop a system based on spatial filtering of jamming signals through the use of an active antenna array which is capable to control its radiation pattern by...
Comparative design of millimeter wave RF-MEMS phase shifters
Kobal, Enis; Demir, Şimşek; Department of Electrical and Electronics Engineering (2016)
Phase shifters are widely used for electronic beam steering for various antenna applications. This thesis presents design and comparison of 3 di erent 3-bit transmission type phase shifters, which are switch-line, Distributed MEMS Transmission Line (DMTL) and triple stub phase shifters, realized with capacitive contact Radio Frequency (RF) Micro-Electro-Mechanical Systems (MEMS) switches for Ka-Band applications. For the design of switch-line phase shifter reducing the sensitivity of the electrical performa...
Interference Supression in GPS Receivers using Spatial Filtering
Erdem, Fatih; Dabak, Omer Can; Sonmez, Tolga; Alatan, Lale; Koç, Seyit Sencer (2016-05-19)
GPS receiver operation can be interrupted by intentional/unintentional jammers even with low power levels. As the jammers become more abundant, protection of critical systems gains importance. In this work, it is aimed to suppress the GPS L1 band jammers using spatial filtering with antenna arrays. After experimental studies, it is achieved to suppress the jammers and to recover the GPS operation in real environment.
Satellite attitude determination based on GPS carrier phase measurements
Özten, Evrim; Tekinalp, Ozan; Department of Aerospace Engineering (2013)
With the developments in the GPS receiver technology, GPS receivers have been preferable equipments also for the space applications. In the early eighties, they have been used only for position, velocity and time determination. With the further improvements, it has been proven that they can provide not only the positioning information, but also attitude knowledge with the accuracy less than 1 degree. In this thesis, an estimation algorithm is developed in the MATLAB Simulink environment for the attitude det...
Design of an X-band 3-bit RF MEMS constant phase shifter
Kuzubaşlı, Ahmet; Akın, Tayfun; Demir, Şimşek; Department of Electrical and Electronics Engineering (2016)
This thesis presents a 3-bit 180° constant phase shifter design implementing Co-Planar Waveguide (CPW) and RF MEMS variable capacitors with ±1.8% accuracy at 10 GHz and ±5.8% maximum peak error between 9-11 GHz. The phase shifter with minimum phase errors is determined by considering exemplary circuit simulations of different phase shifter types designed with a novel in-house RF MEMS fabrication process [1] parameters. Due to its wide-band characteristics and CPW compatibility, the selected topology is the ...
Citation Formats
Ö. C. Dabak, “Design of smart antenna array for interference suppression in GPS,” M.S. - Master of Science, Middle East Technical University, 2016.
METU IIS - Integrated Information Service open@metu.edu.tr