Efficient analysis of large array antennas

Download
2004
Ovalı, Fatih
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) used for the analysis of large, finite arrays is modified for the efficient yet accurate analysis of large printed dipole arrays. In the present hybrid UTD-MoM approach, the number of unknowns to be solved is drastically reduced as compared to the conventional MoM approach, which provides a great efficiency on the computational cost. This extreme reduction in the number of MoM unknowns is carried out by introducing a few UTD-ray type global basis functions for the unknown array element currents. In this study, this hybrid UTD-MoM method is applied to the analysis of a finite, planar periodic array of printed dipoles on a grounded dielectric substrate. The efficiency and accuracy of this hybrid method are demonstrated with some numerical results.

Suggestions

Solution of the antenna palcement problem by means of global optimization techniques
Ural, Mustafa; Kuzuoğlu, Mustafa; Department of Electrical and Electronics Engineering (2010)
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 optima...
High performance readout electronics for uncooled infrared detector arrays
Yıldırım, Ömer Özgür; Akın, Tayfun; Department of Electrical and Electronics Engineering (2006)
This thesis reports the development of high performance readout electronics for resistive microbolometer detector arrays that are used for uncooled infrared imaging. Three different readout chips are designed and fabricated by using a standard 0.6 m CMOS process. Fabricated chips include a conventional capacitive transimpedance amplifier (CTIA) type readout circuit, a novel readout circuit with dynamic resistance nonuniformity compensation capability, and a new improved version of the CTIA circuit. The fabr...
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 ...
Modeling, stability analysis and control system design of a small-sized tiltrotor uav
Çakıcı, Ferit; Leblebicioğlu, Mehmet Kemal; Department of Electrical and Electronics Engineering (2009)
Unmanned Aerial Vehicles (UAVs) are remotely piloted or self-piloted aircrafts that can carry cameras, sensors, communications equipment or other payloads. Tiltrotor UAVs provide a unique platform that fulfills the needs for ever-changing mission requirements by combining the desired features; hovering like a helicopter and reaching high forward speeds like an airplane. In this work, the conceptual design and aerodynamical model of a realizable small-sized Tiltrotor UAV is constructed, the linearized state-...
Citation Formats
F. Ovalı, “Efficient analysis of large array antennas,” M.S. - Master of Science, Middle East Technical University, 2004.