Spectral analysis considerations relevant to radiation and leaky modes of open-boundary microstrip transmission line

Author

Grimm, Jerry Michael ; Nyquist, Dennis P.

Author_Institution

Dept. of Electr. Eng., Michigan State Univ., East Lansing, MI, USA

Volume

41

Issue

1

fYear

1993

fDate

1/1/1993 12:00:00 AM

Firstpage

150

Lastpage

153

Abstract

The continuous radiation spectrum of an open microstrip transmission line and its nonspectral leaky modes are conceptualized through a transform-domain integral-operator formulation and relevant spectral analysis. The radiation spectrum is identified with branch cuts in the axial wavenumber plane, which constrain the migration of branch-point singularities in the transverse wavenumber plane. Leaky-wave modes occur only when the branch cuts in the axial wavenumber plane are violated. The relationship among spectral radiation modes, nonspectral leaky-wave modes, and branch cuts in the axial wavenumber plane is discussed. The influence of branch cuts in the axial wavenumber plane upon the location of branch points in the transverse wavenumber plane is detailed, and a rationale is offered for the choice branch cuts in the latter plane. The formulation is applicable to a wide class of open conducting or dielectric waveguides

Keywords

Green´s function methods; integral equations; microstrip lines; spectral analysis; waveguide theory; branch-point singularities; continuous radiation spectrum; leaky modes; microstrip transmission line; nonspectral leaky modes; open-boundary; spectral analysis; transform-domain integral-operator formulation; transverse wavenumber plane; Conductive films; Dielectrics; Distributed parameter circuits; Microstrip; Planar transmission lines; Scattering; Spectral analysis; Transmission line discontinuities; Transmission line theory; Transmission lines;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.210244

Filename

210244