Design of pattern reconfigurable antennas by using characteristic mode theory

Download
2020-10-22
Aydın, Tolunay
Pattern reconfigurable antennas improve the performance of the system in applications which have dynamic radiation pattern requirements like multi- input multi-output arrays, phased arrays and body area networks. Characteristic mode theory was shown to be useful when investigating the possible orthogonal radiation patterns on an antenna element. Due to improvements in computation capacity of the modern computers, characteristic mode analysis can be used efficiently during the design of pattern reconfigurable antennas. Several types of methods are proposed to excite distinct orthogonal modes on an antenna element in the literature. However, the fundamental idea behind all of these methods can be classified as either excitation by capacitive couplers or excitation by inductive couplers. The main drawback of these methods is their complexity in terms of fabrication. This work proposes a novel method for the excitation of different characteristic modes using only the microstrip feed lines so that the fabrication process can be simplified substantially. The proposed method is optimized for the chosen frequency range and simulated. The radiation patterns of realized configurations are measured and compared with the simulation results. Similarities and discrepancies are discussed. Finally, alternative excitation topologies are illustrated as the possible future work.

Suggestions

Optimizations of Patch Antenna Arrays Using Genetic Algorithms Supported by the Multilevel Fast Multipole Algorithm
Onol, Can; Ergül, Özgür Salih (2014-12-01)
We present optimizations of patch antenna arrays using genetic algorithms and highly accurate full-wave solutions of the corresponding radiation problems with the multilevel fast multipole algorithm (MLFMA). Arrays of finite extent are analyzed by using MLFMA, which accounts for all mutual couplings between array elements efficiently and accurately. Using the superposition principle, the number of solutions required for the optimization of an array is reduced to the number of array elements, without resorti...
Rigorous optimizations of three dimensional antenna arrays using full wave simulations
Onol, Can; Gokce, Ozer; Boyacı, Huseyın; Ergül, Özgür Salih (null; 2015-07-09)
We present optimizations of three-dimensional antenna arrays using heuristic techniques coupled with the multilevel fast multipole algorithm (MLFMA). Without resorting to any periodicity and infinity assumptions, antenna arrays are modeled with surface integral equations and simulated via MLFMA, which also enables the analysis of arrays with non-identical elements. Genetic algorithms and particle swarm optimization methods are employed on the complex data produced by MLFMA in phasor domain to find optimal s...
Design of series-fed printed slot antenna arrays excited by microstrip lines
İncebacak, Mustafa; Alatan, Lale; Department of Electrical and Electronics Engineering (2010)
Series-fed printed slot antenna arrays excited by microstrip lines are low profile, easy to manufacture, low cost structures that found use in applications that doesn’t require high power levels with having advantage of easy integration with microwave front-end circuitry. In this thesis, design and analysis of microstrip line fed slot antenna arrays are investigated. First an equivalent circuit model that ignores mutual coupling effects between slots is studied. A 6-element array is designed by using this e...
Design of Irregularly Shaped Patch Antennas by using the Multiport Network Model
Sener, Goker; Alatan, Lale; Kuzuoğlu, Mustafa (2008-07-11)
The multiport network model (MNM) is an analytical method that is used to analyze microstrip antennas. MNM is based on defining ports along the periphery of the patch and evaluating the impedance matrix corresponding to these ports by using the Greenpsilas function for the cavity under the patch. For regular rectangular, triangular and circular patches, analytical expressions for the Greenpsilas function are available. In the analysis of irregular patches, Greenpsilas functions cannot be calculated explicit...
Design of a multi-layer beam-steering WLAN antenna
Yilmaz, Kardelen; Nesimoglu, Tayfun (2018-11-02)
This paper represents the design of a microstrip patch antenna which is reconfigurable by means of the effect of a pixel grid overlay that is placed at a certain distance from the antenna. hi addition to beam steering capability, this article will focus on several important parameters of the aforementioned antenna, such as, the directivity, the gain, radiation pattern and polarization. The antenna consists three main parts; a rectangular microstrip patch antenna that has the operating frequency at around 2....
Citation Formats
T. Aydın, “Design of pattern reconfigurable antennas by using characteristic mode theory,” M.S. - Master of Science, Middle East Technical University, 2020.