Improving operational performance of antennas on complex platforms by arranging their placements

Bayseferoğulları, Can
The aim of this thesis is to improve the operational performance of the communication antennas mounted on complex platforms such as aircrafts and warships by arranging placements of these antennas. Towards this aim, primarily, in order to gain insight on the influence of geometrically simple structures composing the platform on antenna performance, a quarter wavelength monopole antenna placed at the center of a finite square ground plane is studied by using uniform Geometrical Theory of Diffraction (GTD). Besides, the change of far field radiation pattern and complex diffraction functions due to the variation of the width of a square ground plane is examined. Secondly, electromagnetic analysis of two Ultra High Frequency (UHF) antennas mounted on geometrically simple structures composing simplified F-4 aircraft is carried out by using transient solver of Computer Simulation Technology (CST) Microwave Studio® (MWS), in order to conceive the influence of each structure on antenna performance. Then, electromagnetic analysis of these antennas mounted on simplified and original F-4 aircrafts is performed, in order to determine the optimal location of the lower UHF antenna (newly installed antenna) for the operational performance of this antenna to be optimum in terms of electromagnetic coupling and far field radiation pattern. Finally, electromagnetic analysis of the communication antennas mounted on a warship is performed by using transient solver of CST MWS®, in order to determine the optimal locations of these antennas for the operational performance of these antennas to be optimum in terms of electromagnetic coupling and far field radiation pattern.


Yerlikaya, Umit; Balkan, Raif Tuna (2017-10-13)
Electromechanical actuators are widely used in miscellaneous applications in engineering such as aircrafts, missiles, etc. due to their momentary overdrive capability, long-term storability, and low quiescent power/low maintenance characteristics. This work focuses on electromechanical control actuation systems (CAS) that are composed of a brushless direct current motor, ball screw, and lever mechanism. In this type of CAS, nonlinearity and asymmetry occur due to the lever mechanism itself, saturation limit...
Integrating navigation surveillance of unmanned air vehicles into the civilian national airspaces by using ADS-B applications
Pahsa, Alper; Kaya, Pınar; Alat, Gökçen; Baykal, Buyurman (null; 2011-05-12)
Development of an autopilot for automatic landing of an unmanned aerial vehicle
Arıbal, Seçkin; Leblebicioğlu, Mehmet Kemal; Department of Electrical and Electronics Engineering (2011)
This thesis presents the design of an autopilot and guidance system for an unmanned aerial vehicle. Classical (PID) and modern control (LQT, Sliding Mode) methods for autonomous navigation and landing in adverse weather conditions are implemented. Two different guidance systems are designed in order to navigate through waypoints during normal and/or emergency flight. The nonlinear Pioneer UAV model is used in controller development and simulations. Aircraft is linearized at different trim points and total a...
Application of Beacon Navigation and Angle-Only Artillery Surveying Methods for INS Aiding on Aerial Platforms in GNSS Denied Environments
Guner, D. R. Levent; Özgören, Mustafa Kemal; Platin, Bülent Emre (2013-04-25)
In this work, an alternative navigation scheme for improving the performance of inertial navigation systems onboard guided munitions, missiles and unmanned platforms is investigated, to be used in case of a theater or country-wide GNSS (Global Navigation Satellite System) jamming scenario. Previously laid ground based beacon network is used by the aerial platform's EO/IIR (Electrooptic/ imaging infrared) seeker for bearing-only measurements and position updates are performed by the use of modified artillery...
Modeling and simulation of a small-sized Tiltrotor UAV
Çakıcı, Ferit; Leblebicioğlu, Mehmet Kemal (2012-10-01)
Unmanned aerial vehicles (UAVs) are remotely piloted or self-piloted aircrafts that can carry cameras, sensors, communication equipment and other payloads. Tiltrotor UAVs provide a unique platform that fulfills the needs for ever-changing mission requirements, by combining the desired features of hovering like a helicopter and reaching high forward speeds like an airplane, which might be a force multiplier in the battlefield. In this paper, the conceptual design and aerodynamical model of a realizable small...
Citation Formats
C. Bayseferoğulları, “Improving operational performance of antennas on complex platforms by arranging their placements,” M.S. - Master of Science, Middle East Technical University, 2010.