Improved Finite-Difference Time-Domain Algorithm Based on Error Control for Lossy Materials

Abstract-This paper discusses the development of a reducederror finite-difference time-domain algorithm, capable of handling conducting media in an efficient manner. Founded on a spatially extended stencil, the proposed scheme introduces a novel design procedure, whose basic idea is to enforce conditions of the continuous space to the discrete level. In this way, we derive reliable space-time models for 2-D Maxwell's equations, minimizing the inherent phase and amplitude deviations. A high degree of adaptivity is also accomplished, as the spectral reliability range can be adjusted according to problem-dependent needs. Consequently, an upgraded discretization strategy is provided, which exhibits the same computational complexity with the conventional scheme. Index Terms-Finite-difference time-domain (FDTD) methods, high-order schemes, lossy media, optimized algorithms

A Double-Layer Metamaterial-Based Technique for Interference Mitigation and Shielding of Planar Microwave Structures

An efficient cloaking-shielding technique based on the use of a double superstrate-layer overlay is developed in this paper for planar microstrips. The metamaterial-inspired formulation reduces considerably the induced on the strip current and the reflected from the microstrip electric field, thus alleviating the electromagnetic susceptibility of microstrip transmission lines. For this purpose, the mathematical analysis and optimization procedure are founded on a semianalytic integral equation algorithm, while a set of numerical results certifies its promising merit

A Double-Layer Metamaterial-Based Technique for Interference Mitigation and Shielding of Planar Microwave Structures

An efficient cloaking-shielding technique based on the use of a double superstrate-layer overlay is developed in this paper for planar microstrips. The metamaterial-inspired formulation reduces considerably the induced on the strip current and the reflected from the microstrip electric field, thus alleviating the electromagnetic susceptibility of microstrip transmission lines. For this purpose, the mathematical analysis and optimization procedure are founded on a semianalytic integral equation algorithm, while a set of numerical results certifies its promising merit

Enhanced Design of Narrowband Filters Based on The Extraordinary Transmission Through Single Fishnet Structures

A systematic method for the efficient design of narrowband filters founded on the extraordinary transmission via single fishnet structures (SFSs) is presented in this paper. Essentially, due to its strong resonant behavior, this phenomenon is proven suitable for the implementation of high-Q devices. The new design formulas are derived through the combination of full-wave numerical simulations and curve fitting algorithms. Also, adequate mathematical criteria are defined for the evaluation of the filters\u27 linear performance, indicating that the transmitted electromagnetic waves remain practically undistorted in the frequency band of interest. Then, by exploiting the previously developed relations, proper correction factors are introduced in the existing SFS equivalent circuit expressions, which hardly increase the overall computational complexity. This quantitative modification leads to an enhanced characterization of SFSs, as key components for diverse applications. Finally, several limitations as well as possible ways of extending the featured algorithm to more complicated structures and higher frequency bands are briefly discussed

CALCULATION OF INDUCTANCE, RESISTANCE AND CAPACITANCE BY DIRECT METHODS OF FUNCTIONAL ANALYSIS

THE ABOVE THESIS IS DEALT WITH THE APPLICATION OF DIRECT VARIATIONAL METHODS (E.G. RAYLEIGH-RITZ METHOD, GALERKIN METHOD, KANTOROVICH METHOD) FOR THE CALCULATION OF RESISTANCE, INDUCTANCE AND CAPACITANCE. THE ESTIMATION OF INTERNAL INDUCTANCE OF HIGHLY PERMEABLE CONDUCTORS (M>>M) WITH VAROUS CROSS-SECTIONS IS ONE OF THE MAIN OBJECTIVES IN THE FIRST PART OF THE THESIS, WHERE THE RESULTS ARE COMPARED WITH THE RESULTS OBTAINED BY USING THE FINITE ELEMENT METHOD. THE SECONDPART OF THE THESIS IS DEALT WITH A METHOD WHICH IS ESSENTIALLY A SPECIALIZATION OF THE "RAYLEIGH-MAXWELL" METHOD. THE PROPOSED METHOD IS USED FOR OBTAINING DUAL BOUNDS FOR VARIOUS FIELD PARAMETERS SUCH AS RESISTANCE AND CAPACITANCE.ΣΤΗΝ ΠΙΟ ΠΑΝΩ ΔΙΑΤΡΙΒΗ ΓΙΝΕΤΑΙ ΕΦΑΡΜΟΓΗ ΤΩΝ ΑΜΕΣΩΝ ΜΕΘΟΔΩΝ ΤΟΥ ΛΟΓΙΣΜΙΚΟΥ ΤΩΝ ΜΕΤΑΒΟΛΩΝ (RAYLEIGH-RITZ, GALERKIN, KANTOROVICH) ΓΙΑ ΤΟΝ ΥΠΟΛΟΓΙΣΜΟ ΤΗΣ ΑΥΤΕΠΑΓΩΓΗΣ, ΤΗΣ ΑΝΤΙΣΤΑΣΗΣ ΚΑΙ ΤΗΣ ΧΩΡΗΤΙΚΟΤΗΤΑΣ. Ο ΠΡΟΣΕΓΓΙΣΤΙΚΟΣ ΑΝΑΛΥΤΙΚΟΣ ΠΡΟΣΔΙΟΡΙΣΜΟΣ ΤΗΣ ΑΥΤΕΠΑΓΩΓΗΣ ΣΙΔΗΡΟΜΑΓΝΗΤΙΚΩΝ ΑΓΩΓΩΝ (Μ>>Μ) ΔΙΑΦΟΡΩΝ ΔΙΑΤΟΜΩΝ ΑΠΟΤΕΛΕΙΕΝΑΝ ΑΠΟ ΤΟΥΣ ΚΥΡΙΟΥΣ ΑΝΤΙΚΕΙΜΕΝΙΚΟΥΣ ΣΤΟΧΟΥΣ ΣΤΟ ΠΡΩΤΟ ΜΕΡΟΣ ΤΗΣ ΔΙΑΤΡΙΒΗΣ. ΓΙΑ ΤΗ ΣΥΓΚΡΙΣΗ ΚΑΙ ΤΟΝ ΕΛΕΓΧΟ ΤΩΝ ΑΠΟΤΕΛΕΣΜΑΤΩΝ ΤΟΥ ΠΡΩΤΟΥ ΜΕΡΟΥΣ ΧΡΗΣΙΜΟΠΟΙΕΙΤΑΙ Η ΑΡΙΘΜΗΤΙΚΗ ΜΕΘΟΔΟΣ ΤΩΝ ΠΕΠΕΡΑΣΜΕΝΩΝ ΣΤΟΙΧΕΙΩΝ. ΤΟ ΔΕΥΤΕΡΟ ΜΕΡΟΣ ΤΗΣ ΔΙΑΤΡΙΒΗΣ ΠΕΡΙΛΑΜΒΑΝΕΙ ΟΥΣΙΑΣΤΙΚΑ ΜΙΑ ΕΞΕΙΔΙΚΕΥΣΗ ΤΗΣ ΜΕΘΟΔΟΥ RAYLEIGH-MAXWELL ΣΤΟΝ ΥΠΟΛΟΓΙΣΜΟ ΔΥΑΔΙΚΩΝ ΦΡΑΓΜΑΤΩΝ ΔΙΑΦΟΡΩΝ ΠΕΔΙΑΚΩΝ ΠΑΡΑΜΕΤΡΩΝ ΟΠΩΣ ΓΙΑ ΠΑΡΑΔΕΙΓΜΑ ΕΙΝΑΙ Η ΑΝΤΙΣΤΑΣΗ ΚΑΙ Η ΧΩΡΗΤΙΚΟΤΗΤΑ

Modern EMC analysis I: time-domain computational schemes

The objective of this two-volume book is the systematic and comprehensive description of the most competitive time-domain computational methods for the efficient modeling and accurate solution of contemporary real-world EMC problems. Intended to be self-contained, it performs a detailed presentation of all well-known algorithms, elucidating on their merits or weaknesses, and accompanies the theoretical content with a variety of applications. Outlining the present volume, the analysis covers the theory of the finite-difference time-domain, the transmission-line matrix/modeling, and the finite

Modern EMC analysis techniques II: models and applications

The objective of this two-volume book is the systematic and comprehensive description of the most competitive time-domain computational methods for the efficient modeling and accurate solution of modern real-world EMC problems. Intended to be self-contained, it performs a detailed presentation of all well-known algorithms, elucidating on their merits or weaknesses, and accompanies the theoretical content with a variety of applications. Outlining the present volume, numerical investigations delve into printed circuit boards, monolithic microwave integrated circuits, radio frequency microelectr