Title :
Nonreciprocal left-handed transmission characteristics of microstriplines on ferrite substrate
Author :
Ueda, T. ; Tsutsumi, M.
Author_Institution :
Dept. of Electron., Kyoto Inst. of Technol.
fDate :
4/1/2007 12:00:00 AM
Abstract :
In this paper, a nonreciprocal left-handed transmission line has been investigated. It is composed of a normally magnetised ferrite microstripline periodically loaded with lumped capacitances and inductive stubs. Based on the simple equivalent circuit model for a predominant edge guided mode, the dispersion relation of the ferrite left-handed transmission line has been estimated, providing the backward wave characteristic in the positive and negative permeability frequency regions. With the aid of the finite element method, it is confirmed that specific three-dimensional structures do show left-handed characteristics as well as the nonreciprocity. Nonreciprocal transmission characteristics with the isolation of more than 30 dB are obtained numerically and demonstrated experimentally in the positive and negative permeability frequency regions, for the edge guided modes. It is explained that the nonreciprocity of the ferrite left-handed transmission line is caused by the leaky wave phenomenon from the microstrip to the ferrite substrate
Keywords :
dispersion relations; equivalent circuits; ferrites; finite element analysis; magnetic permeability; metamaterials; microstrip lines; backward wave characteristics; dispersion relation; equivalent circuit model; ferrite substrate; finite element method; inductive stub; leaky wave phenomenon; lumped capacitances; magnetised ferrite microstripline; negative permeability frequency region; nonreciprocal left-handed transmission line; positive permeability frequency region; predominant edge guided mode; three-dimensional structures;
Journal_Title :
Microwaves, Antennas & Propagation, IET
DOI :
10.1049/iet-map:20050006
