Solution of the antenna palcement problem by means of global optimization techniques

Ural, Mustafa
In this thesis work, minimization of platform-based coupling between the antennas of two VHF radios on an aircraft platform and two HF radios on a ship platform is aimed. For this purpose; an optimal antenna placement, which yields minimum average coupling between the antennas over the whole frequency band of operation is determined for each platform. Two important global optimization techniques, namely Genetic Algorithm Optimization and Particle Swarm Optimization, are used in determination of these optimal antenna placements. Aircraft & ship platforms and antennas placed on them are modeled based on their real electrical and physical properties in CST – MWS (Microwave Studio) simulation tool. For each platform, antenna placements and coupling results determined by two different optimization techniques and performances of these optimization techniques are compared with each other. At the end of this thesis work; for each platform, far-field radiation pattern performances of the antennas at their optimal places are analyzed in terms of directivity and coverage.


Efficient analysis of large array antennas
Ovalı, Fatih; Aydın Çivi, Hatice Özlem; Department of Electrical and Electronics Engineering (2004)
Large phased array antennas are widely used in many military and commercial applications. The analysis of large arrays containing many antenna or frequency-selective (FSS) surface elements is inefficient or intractable when brute force numerical methods are used. For the efficient analysis of such structures hybrid methods (analytic and numerical, numerical and numerical) can be used. In this thesis, a hybrid method combining the uniform geometrical theory of diffraction (UTD) and the moment method (MoM) us...
Development of a pc numerical system for high voltage sphere gap control
Kasap, Onur; Hızal, Mirzahan; Department of Electrical and Electronics Engineering (2005)
In this thesis, a high precision motion and position control system has been developed and applied to a high voltage sphere gap control and measurement system. The system is able to support up to 3-axes position and motion control. The control system includes a microcontroller card, three DC servo motor driver cards and a data storage unit. To provide communication between computer and motion control system, the Universal Serial Bus (USB) port is used. The microcontroller card is equipped with an USB interf...
Analysis and design of passive microwave and optical devices using the multimode interference technique
Sunay, Ahmet Sertaç; Birand, Mehmet Tuncay; Department of Electrical and Electronics Engineering (2005)
The Multimode Interference (MMI) mechanism is a powerful toool used in the analysis and design of a certain class of optical, microwave and millimeter wave devices. The principles of the MMI method and the self-imaging principle is described. Using this method, NXM MMI couplers, MMI splitter/combiners are analyzed. Computer simulations for illustrating the "Multimode Interference Mechanism" are carried out. The MMI approach is used to analyze overmoded 'rectangular metallic' and 'dielectric slab' type of wa...
Milimeter wave microstrip launchers and antenna arrays
Akgün, Erdem; Hızal, Altunkan; Department of Electrical and Electronics Engineering (2006)
Coaxial-to-microstrip launcher and microstrip patch array antenna are designed to work at center frequency of 36.85 GHz with a bandwidth higher than 300 MHz. The antenna array design also includes the feeding network distributing the power to each antenna element. The design parameters are defined on this report and optimized by using an Electromagnetic Simulation software program. In order to verify the theoretical results, microstrip patch array antenna is produced as a prototype. Measurements of antenna ...
Cmos class e power amplifier modelling and design including channel resistance effects
Demir, İbrahim; Demir, Şimşek; Department of Electrical and Electronics Engineering (2004)
CMOS is the favorite candidate process for the high integration of the wireless communication IC blocks, RF frontend and digital baseband circuitry. Also the design of the RF power amplifier stage is the one of the most important part of the RF CMOS circuit design. Since high frequency and high power simultaneously exists on this stage, devices works on the limits of the process. Therefore standard device models may not be valid enough for a successful design. In the thesis high frequency passive device and...
Citation Formats
M. Ural, “Solution of the antenna palcement problem by means of global optimization techniques,” M.S. - Master of Science, Middle East Technical University, 2010.