Investigation of tightly coupled arrays for wideband applications

Download

12625830.pdf

Date

2020-10

Author

Arda, Kaan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

423
views

297
downloads

This thesis aims to provide in depth research on tightly coupled dipole arrays to be used in ultrawideband apertures applications. First, operation principles of tightly coupled dipole arrays are investigated. Starting from the Wheeler’s current sheet aperture concept, some calculations on bandwidth and impedance concepts are conducted. B.A. Munk’s addition to the concept, use of capacitive elements between adjacent dipoles, are introduced. Array unit cell is modeled using equivalent circuit approach, bandwidth and input impedance calculations are conducted using MATLAB environment. Unit cell designs using two different capacitive coupling mechanisms are given. Optimized final unit cell products that satisfy theoretical bandwidth and pattern requirements are given. Simulations are conducted for determination of number of resistive terminations in tightly coupled arrays. Discussions on number of dummy elements are given. Series of example finite array analyses are conducted. A finite array design that is producible using PCB technology is given. Antenna unit cell is modified in a finite array environment, due to the fact that finite PCB size that restricts maximum number of elements. An ultrawideband aperture that satisfies the theoretical limits is designed using this finite aperture area. Different array feeding mechanism are given to be used as proposed antenna’s feed. Various kinds of feed mechanisms are investigated, only a portion amongst them are determined that they do perform well. Manufacturing process of finite array is given along with the measurement results. Similarity between measurements and simulations are discussed.

Subject Keywords

Array feeding, Finite arrays, Antenna miniaturization, Wideband array antennas, Tightly coupled dipole arrays

URI

https://hdl.handle.net/11511/69181

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Analysis and design of slotted substrate integrated waveguide antenna on cylindrical surface Bayraktar, Ömer; Aydın Çivi, Hatice Özlem; Department of Electrical and Electronics Engineering (2014) This thesis presents novel traveling wave conformal shunt slot arrays on cylindrical substrate integrated waveguide (CSIW) placed on a cylindrical surface in the circumferential direction at K-band. Mutual couplings of longitudinal slots on broad wall of CSIW are formulated and active admittance formulas of the slots are derived which are used in Elliott’s design procedure to design slotted CSIW arrays. The designs are carried out at 25 GHz using non-uniform and uniform slot separations. The non uniform slo...
Beam Steerable Traveling Wave Meander Line Antenna Using Varactor Diode for X-Band Applications Gokalp, Nihan; Aydın Çivi, Hatice Özlem (2008-07-11) This paper presents a novel beam steerable meander line antenna with varactor diode for X-band applications. Beam steering has been achieved by loading the arms of the meander line antenna with varactor diodes. The capacitances of the varactor diodes have been controlled by DC bias voltage. Instead of varactor diodes, RF-MEMS variable capacitances can be used to scan the beam. Since the insertion loss of MEMS capacitances are small compared to loss of varactor diodes, use of MEMS capacitors will increase th...
35 GHz phased array antenna using DMTL phase shifters Guclu, Caner; Cetintepe, Cagri; Aydın Çivi, Hatice Özlem; Demir, Şimşek; Akın, Tayfun (2010-08-27) This paper presents the design of a monolithic phased array antenna with DMTL phase shifters on quartz substrate operating at 35 GHz. The design integrates DMTL phase shifters, rectangular slot antennas with the feed network comprising CPW lines, CPW T-junction and corners. On the four branches of the antenna, there are 5-bit phase shifters using 31 MEMS bridges, covering 360° with a resolution of 11.25°.
On the Poisson sum formula for the analysis of wave radiation and scattering from large finite arrays Aydın Çivi, Hatice Özlem; Chou, HT (1999-05-01) Poisson sum formulas have been previously presented and utilized in the literature [1]-[8] for converting a finite element-by-element array field summation into an alternative representation that exhibits improved convergence properties with a view toward more efficiently analyzing wave radiation/scattering from electrically large finite periodic arrays. However, different authors [1]-[6] appear to use two different versions of the Poisson sum formula; one of these explicitly shows the end-point discontinui...
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...

Citation Formats

K. Arda, “Investigation of tightly coupled arrays for wideband applications,” M.S. - Master of Science, Middle East Technical University, 2020.