• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.4
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• pp.384-392
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• 2003

In this study, the electromagnetic coupling through a narrow transverse slit in the upper wall of a parallel-plate waveguide(PPW) covered by a dielectric slab with a nearby conducting strip on the slab is considered. Two contrastive coupling phenomena, cavity-type and parasitic-type, observed in the geometry have been distinguished by differences in the resonant strip lengths and offset positions, induced strip current, radiation pattern, frequency bandwidth, and electromagnetic field distributions near the coupling slit.

• Journal of electromagnetic engineering and science
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• v.5 no.3
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• pp.105-111
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• 2005

This paper presents the basic characteristics of a cutoff cavity-backed aperture antenna with a feed post and a parasitic post inserted parallel to the aperture. It is shown that this type of antenna forcibly resonates the cutoff cavity by adding a single external reactance to the parasitic post. The Galerkin's method of moments is used to analyze integral equations for the unknown electric current on each post and the aperture electric field on the aperture. The value of an external reactance for forced resonance is analytically obtained by deriving a determining equation. Also the current distribution on each post, aperture electric field distributions, and the radiation patterns are discussed. The theoretical analysis is verified by the measured return loss and radiation patterns.

• Journal of electromagnetic engineering and science
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• v.1 no.1
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• pp.37-42
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• 2001

This paper presents the basic characteristics of a cutoff cavity-hacked slot antenna, for the application of spacetenna, with a feed post and a parasitic post inserted parallel to the slot. This type of antenna might effectively excite the slot and forcibly resonate the cavity by adding external reactance to the parasitic post. The Galerkin\`s method of moments is used to analyze integral equations for the unknown electric current on each post and electric field in the slot. The value of external reactance for forced resonance is discussed by deriving a determining equation, the current distribution on each post and the radiation patterns are considered. The analysis is in excellent agreement with the experiment for the radiation patterns.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.20-24
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• 2001

Two types of radiative coupling in the 2-dimensional aperture to scatterer coupling problems are described with an emphasis on the main difference between the two types. In particular, detailed comparison is made from the viewpoint of the Quality factor between two types.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.459-463
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• 2003

A circularly polarized microstrip patch antenna (MPA) using electromagnetic (EM) coupled fed method is analyzed in view of the two types of coupling mechanisms viz. cavity and parasitic type, proposed earlier. The patch-ground plane distance is varied in order to achieve the fore-mentioned types of couplings. For each case of patch-ground plane distance, the offset position of feedline is optimized for perfect matching and the boresight axial ratio (AR) is observed. It is seen that CP operation is possible only for cavity-type coupling (smaller patch-ground plane distances). The simulated results for the boresight AR for the two types of coupling mechanisms are presented.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.259-262
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• 2002

The problems of electromagnetic coupling and radiation in an aperture-coupled microstrip antenna structure are discussed while focusing on the difference between two representative field configuration: parasitic-type and cavity-type. Based on the discussion, a critical look is taken at the validity of a previous description of the coupling mechanism of m aperture-coupled microstrip antenna.