Theoretical Investigation on an Array of Dual Tuned Staggered Dipole Apertures by the Method of Moment and Comparison with Experimental Results (original) (raw)
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Journal of Microwaves, Optoelectronics and Electromagnetic Applications, 2017
There are several techniques for optimization of Frequency Selective Surfaces (FSS). Generally, in literature, we can find a few articles about the Taguchi's method applied in electromagnetic. This method is based on orthogonal arrays (OAs) and it is a procedure that reduces the number of iterations required in an optimization process. For a FSS optimization using the crossed dipole geometry, the Taguchi's method, in combination of the equivalent circuit method, is used for the first time. Here, we applied the method for synthesis of FSS with crossed dipole geometry. The results show that the parameters, of the synthesized FSS, are extracted in an easy and successful way. A prototype was built for validation purpose.
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IEE Proceedings - Microwaves, Antennas and Propagation, 2000
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Electromagnetic Shielding of Resonant Frequency-Selective Surfaces in Presence of Dipole Sources
The shielding problem consisting in the interaction between a dipole source and a Frequency-Selective Surface (FSS) is investigated. The Array Scanning Method (ASM) is adopted to take into account all the propagating and evanescent waves, which constitute the spectrum of the dipole and all the propagating and evanescent Floquet modes, which constitute the spectrum of the diffracted field by the FSS. The main differences with respect to the shielding of a conventional plane-wave source are pointed out, especially in terms of resonant frequencies, operating bandwidth and transmission levels.
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Two important features of a frequency selective surface (FSS) are bandwidth and frequency stability. Methods of increasing FSS bandwidth include, among others, decreasing inter-element spacing and increasing the thickness of the supporting dielectric layer. The shape of the FSS element also determines its bandwidth. To achieve any desired bandwidth, a combination of these methods is often required. The present work focuses on designing an FSS element where shape alone is the most important feature in determining its bandwidth. The elements are a combination of two known FSS elements with close resonant frequencies but not located in the same frequency band. The FSS's are designed to act as reflectors. The second part of this paper discusses frequency stabilization techniques, focusing on rectangular arrays of tripoles and cross dipoles. These elements have poor frequency stability with angle of incidence for parallel polarization. Dielectric loading and skewed arrays help minimize the problem. In the present work, a new method based on varying the element's impedance by partially removing the conducting patch at the center of the element is introduced.