Author

# Antonije R. Djordjevic

Other affiliations: University of Illinois at Chicago, Serbian Academy of Sciences and Arts, DuPont ...read more

Bio: Antonije R. Djordjevic is an academic researcher from University of Belgrade. The author has contributed to research in topics: Microstrip & Integral equation. The author has an hindex of 24, co-authored 127 publications receiving 2864 citations. Previous affiliations of Antonije R. Djordjevic include University of Illinois at Chicago & Serbian Academy of Sciences and Arts.

##### Papers published on a yearly basis

##### Papers

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01 May 1989TL;DR: In this paper, several techniques for the computation of the line response, starting from the known circuit-theory parameters, are presented and evaluated, such as time-stepping solution of the telegrapher equations, modal analysis in the time domain, model analysis in frequency domain, and a convolution technique which uses line Green's functions.

Abstract: Evaluation of the time-domain response of multiconductor transmission lines is of great importance in the analysis of the crosstalk in fast digital circuit interconnections, as well as in the analysis of power lines. Several techniques for the computation of the line response, starting from the known circuit-theory parameters, are presented and evaluated. These methods are: time-stepping solution of the telegrapher equations, modal analysis in the time domain, model analysis in the frequency domain, and a convolution technique which uses line Green's functions. The last method can treat the most general case of lossy transmission lines with nonlinear terminal networks. Numerical and experimental results are presented to illustrate these techniques and to give insight into the crosstalk problems in fast digital circuits.

325 citations

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TL;DR: Measurements for the complex permittivity of FR-4 from power frequencies up to the microwave region are presented and simple closed-form expressions are given that approximate the measured data and provide a causal response in the time domain.

Abstract: FR-4 is one of the most widely used dielectric substrates in the fabrication of printed circuits for fast digital devices. This material exhibits substantial losses and the loss tangent is practically constant over a wide band of frequencies. This paper presents measured data for the complex permittivity of this material from power frequencies up to the microwave region. In addition it gives simple closed-form expressions that approximate the measured data and provide a causal response in the time domain.

321 citations

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TL;DR: In this article, a novel method for transient analysis of Iossy transmission lines with arbitrary nonlinear terminal networks is presented, where the uniqueness of this approach is that they develop time-domain Green's functions for the multiport transmission-line systems by terminating the ports in quasi-matched loads.

Abstract: A novel method for transient analysis of Iossy transmission lines with arbitrary nonlinear terminal networks is presented. The uniqueness of this approach is that we develop time-domain Green's functions for the multiport transmission-line systems by terminating the ports in quasi-matched loads. This ensures Green's functions of a short duration. Hence, the amount of frequency-domain data necessary to obtain time-domain Green's functions is modest. These Green's functions are then convolved with the line port voltages. With this technique one can analyze responses of multiconductor transmission lines with arbitrary nonlinear loads (even with memory) as we have at any instant of time Thevenin's equivalent of the linear portion of the system. An example is presented to illustrate the application of this technique to multiconductor nonlinearly loaded transmission lines.

187 citations

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TL;DR: In this paper, a general technique was proposed to compensate these currents and suppress radiation in horizontal directions, where dielectric polarization currents were identified as the physical sources of this radiation.

Abstract: Microstrip (patch) antennas usually strongly radiate in directions along the ground plane. This effect causes unwanted radiation patterns and increased coupling among array elements. Dielectric polarization currents are identified as physical sources of this radiation. A general technique is proposed to compensate these currents and suppress radiation in horizontal directions.

173 citations

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TL;DR: In this article, the authors considered a system consisting of an arbitrary number of multiconductor transmission lines joined and terminated by arbitrary linear networks, and analyzed the system in the frequency domain, and the inverse Fourier transform was used to obtain the time-domain response.

Abstract: Systems are considered consisting of an arbitrary number of multiconductor transmission lines joined and terminated by arbitrary linear networks. The fines are assumed to be Iossy, with frequency-dependent parameters. The system is analyzed in the frequency domain, and the inverse Fourier transform is used to obtain the time-domain response.

168 citations

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24 May 1988TL;DR: In this paper, the authors outline a methodology for the computation of the response of a multiconductor transmission line terminated by linear networks, where the lines are embedded in a multilayered lossy dielectric media and have arbitrary cross sections, but uniform along the length.

Abstract: The objective of this paper is to outline a methodology for the computation of the response of a multiconductor transmission line terminated by linear networks. The lines are embedded in a multilayered lossy dielectric media and have arbitrary cross sections, but uniform along the length. To check the accuracy of the theoretical results, extensive experimental verification has been carried out.

1,307 citations

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TL;DR: The matrix pencil method is described, which is more robust to noise in the sampled data and has a lower variance of the estimates of the parameters of interest than a polynomial-type method, and is also computationally more efficient.

Abstract: The approximation of a function by a sum of complex exponentials is a problem that is at least two centuries old. Fundamentally, all techniques discussed in this article proceed from using the same sequence of data samples and vary only, but importantly, in how those samples are used in achieving the parameter estimation. All of these techniques, in other words, seek the same quantitative parameters to represent the sampled data, but use different routes to get there. The techniques for estimating the parameters are either linear or nonlinear. The linear techniques are emphasized in this presentation. In particular, the matrix pencil method is described, which is more robust to noise in the sampled data. The matrix pencil approach has a lower variance of the estimates of the parameters of interest than a polynomial-type method (Prony's method belongs to this category), and is also computationally more efficient. A bandpass version of the matrix pencil can be implemented in hardware, utilizing an AT&T DSP32C chip operating in real time. A copy of the computer program implementing the matrix pencil technique is given in the appendix. >

1,153 citations

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TL;DR: Analysis of the molecular geometries and energetics in these materials reveals a correlation between electron mobility and substituent-induced arylene core distortion, while Vth and I(off) are generally affected by LUMO ener getics.

Abstract: Structural and electronic criteria for ambient stability in n-type organic materials for organic field-effect transistors (OFETs) are investigated by systematically varying LUMO energetics and molecular substituents of arylene diimide-based materials Six OFETs on n+-Si/SiO2 substrates exhibit OFET response parameters as follows: N,N'-bis(n-octyl)perylene-3,4:9,10-bis(dicarboximide) (PDI-8): mu = 032 cm2 V(-1) s(-1), Vth = 55 V, I(on)/I(off) = 10(5); N,N'-bis(n-octyl)-1,7- and N,N'-bis(n-octyl)-1,6-dibromoperylene-3,4:9,10-bis(dicarboximide) (PDI-8Br2): mu = 3 x 10(-5) cm2 V(-1) s(-1), Vth = 62 V, I(on)/I(off) = 10(3); N,N'-bis(n-octyl)-1,6,7,12-tetrachloroperylene-3,4:9,10-bis(dicarboximide) (PDI-8Cl4): mu = 4 x 10(-3) cm2 V(-1) (s-1), Vth = 37 V, I(on)/I(off) = 10(4); N,N'-bis(n-octyl)-2-cyanonaphthalene-1,4,5,8-bis(dicarboximide) (NDI-8CN): mu = 47 x 10(-3) cm2 V(-1) s(-1), Vth = 28, I(on)/I(off) = 10(5); N,N'-bis(n-octyl)-1,7- and N,N'-bis(n-octyl)-1,6-dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDI-8CN2): mu = 013 cm2 V(-1) s(-1), Vth = -14 V, I(on)/I(off) = 10(3); and N,N'-bis(n-octyl)-2,6-dicyanonaphthalene-1,4,5,8-bis(dicarboximide) (NDI-8CN2): mu = 015 cm2 V(-1) s(-1), Vth = -37 V, I(on)/I(off) = 10(2) Analysis of the molecular geometries and energetics in these materials reveals a correlation between electron mobility and substituent-induced arylene core distortion, while Vth and I(off) are generally affected by LUMO energetics Our findings also indicate that resistance to ambient charge carrier trapping observed in films of N-(n-octyl)arylene diimides occurs at a molecular reduction potential more positive than approximately -01 V (vs SCE) OFET threshold voltage shifts between vacuum and ambient atmosphere operation suggest that, at E(red1) -01 V, the trap density increase is negligible OFETs fabricated with the present n-type materials having E(red1) > -01 V operate at conventional gate biases with minimal hysteresis in air This reduction potential corresponds to an overpotential for the reaction of the charge carriers with O2 of approximately 06 V N,N'-1H,1H-Perfluorobutyl derivatives of the perylene-based semiconductors were also synthesized and used to fabricate OFETs, resulting in air-stable devices for all fluorocarbon-substituted materials, despite generally having E(red1) < -01 V This behavior is consistent with a fluorocarbon-based O2 barrier mechanism OFET cycling measurements in air for dicyanated vs fluorinated materials demonstrate that energetic stabilization of the charge carriers results in greater device longevity in comparison to the OFET degradation observed in air-stable semiconductors with fluorocarbon barriers

976 citations

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TL;DR: In this paper, a compact representation of the electric and magnetic-type dyadic Green's functions for plane-stratified, multilayered, uniaxial media based on the transmission-line network analog along the aids normal to the stratification is given.

Abstract: A compact representation is given of the electric- and magnetic-type dyadic Green's functions for plane-stratified, multilayered, uniaxial media based on the transmission-line network analog along the aids normal to the stratification. Furthermore, mixed-potential integral equations are derived within the framework of this transmission-line formalism for arbitrarily shaped, conducting or penetrable objects embedded in the multilayered medium. The development emphasizes laterally unbounded environments, but an extension to the case of a medium enclosed by a rectangular shield is also included.

774 citations

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TL;DR: In this paper, an accurate and general procedure for the analysis of electromagnetic radiation and scattering by perfectly conducting objects of arbitrary shape embedded in a medium consisting of an arbitrary number of planar dielectric layers is developed.

Abstract: An accurate and general procedure for the analysis of electromagnetic radiation and scattering by perfectly conducting objects of arbitrary shape embedded in a medium consisting of an arbitrary number of planar dielectric layers is developed. The key step in this procedure is a formulation of the so-called mixed-potential electric field integral equation (MPIE) that is amenable to an existing advanced solution technique developed for objects in free space and that employs the method of moments in conjunction with a triangular-patch model of the arbitrary surface. Hence, the goal is to immediately increase analysis capabilities in electromagnetics, yet remain compatible with the large existing base of knowledge concerning the solution of surface integral equations. Three alternative forms of the MPIE in plane-stratified media are developed, and their properties are discussed. One of the developed MPIEs is used to analyze scatterers and antennas of arbitrary shape that penetrate the interface between contiguous dielectric half-spaces. >

773 citations