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Transmission Line Method (transmission + line_method)

Distribution by Scientific Domains
Physics and Astronomy50%

Selected Abstracts

Transverse transmission line method to analyze stop-band microwave filters

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2007
A. L. P. S. Campos
Abstract In this article, we consider the analysis of stop-band microwave filters using periodic structures on isotropic substrates with dielectric losses. Frequency selective surfaces composed by an array of rectangular conducting patch elements are considered to compose the stop-band filters. This analysis uses the method of moments in combination with the transverse transmission line method, in the Fourier domain, to determine the scattering characteristics of the considered structures. A good agreement with the results presented by the other authors is observed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2678,2681, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22856 [source]

The effect of oxygen content on the electrical characteristics of ZnO

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2007
E. S. Jung
Abstract This work presents the influence of the variation of oxygen content in the ZnO films on their electrical characteristics. We applied the post-thermal annealing in N2 and air ambient to control the oxygen content of ZnO films, which improved crystallinity and optical properties of ZnO films. The oxygen concentration was measured by Auger electron spectroscopy and the electrical characteristics were obtained by Hall measurement in the van der Pauw configuration and transmission line method. As result, it was shown that the electron concentration varies from 1016 to 1021/cm3, while the resistivity from 10,3 to tens ohm-cm with respect to Zn/O concentration ratio. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Oxidation treatment on Ni/Au Ohmic contacts to p-type GaN

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003
Z. Z. Chen
Abstract Current,voltage (I,V) characteristics, transmission line method (TLM), and optical transmittance measurements are performed to investigate the effects of thermal oxidation and plasma-induced oxidation treatments on Ni/Au contacts to p-type GaN. Whether oxidation and thermal annealing are performed simultaneously or in succession, the specific contact resistances of Au/Ni/p-GaN are reduced. As to plasma-induced oxidation, neither no-oxidation nor long-time oxidation treatments on Ni/Au layers are suitable for obtaining a low-resistance Ohmic contact. The roles of oxidation are believed to activate the Mg acceptor in p-GaN and to form an oxygenous intermediate semiconductor layer, which may lower the Schottky barrier height between the metal layer and p-GaN. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]