Modellierung konformer Apertur-Gruppenantennen mit Mode-Matching und hybriden Boundary-Element-Method-, Mode-Matching-Verfahren

This work deals with the theoretical principles of two exact methods (full-wave methods) for the electromagnetic computer-aided design of conformal array antennas. Typical configurations of antenna elements on curved surfaces are investigated based on these methods. With respect to the available electromagnetic modelling methods conformal array antennas are divided into two classes. The distinction is drawn depending on the existence of analytical modal solutions of the boundary value problem given by the carrier structure. In case of the existence of an analytical solution it is possible to develop a very efficient partly analytical modelling method. Otherwise, a general fully numerical method has to be applied, which does not make any assumptions about the carrier structure. Thus, two different methods are presented. The first part of this work deals with a method for sector arrays of waveguide-fed aperture elements on circular metal cylinders. Concentric layers of homogeneous materials may be placed both outside the metal cylinder and inside the feeding waveguides. The modelling method is based on the use of generalized scattering matrices, which are set up by a "mode-matching" (MM) technique. A pattern synthesis method, which is essential with respect to the application of the array antenna, is also presented. It is based on an invertive mathematical approach and due to the modelling by a full-wave method all physical effects introduced by the antenna configuration are implicitly taken into account. The software, which has been developed based on this approach, can be used for investigations on radiation properties (pattern synthesis), as well as element matching, mutual coupling and - using a cylindrical wave transformation - scattering (RCS or SW). The second part of this work presents the basics of a fully numerical hybrid method for the design of waveguide-fed aperture elements embedded into arbitrarily shaped metal surfaces. The metal surfaces are modelled by a boundary integral method called "boundary element method" (BEM). A magnetic field integral equation (MFIE) is set up and solved numerically by a method of moments (MoM). Surfaces with small radii of curvature are efficiently modelled by an extension of the classical formulation of the BEM. The apertures are included in this formulation by a novel combination of the integral equation method with a "mode-matching" (MM) technique. This combination can be called "hybrid BEM/MM" and may be applied to the investigation of radiation, mutual coupling and scattering problems taking into account the complete antenna configuration including the arbitrarily shaped carrier structure.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2003

Author dc:creator

• Bertuch, Thomas

Contributors dc:contributor

• Rembold, Bernhard

• info:eu-repo/classification/ddc/620
• Ingenieurwissenschaften
• Antennenmodellierung
• konforme Antennen
• Gruppenantennen
• Diagrammsynthese
• mode-matching
• boundary element method
• Momentenmethode
• Hybridverfahren

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123120%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:61457