Summary

International Symposium on Antennas and Propagation

2010

Session Number:4FA4

Session:

Number:4FA4-3

Circular Polarized Antenna with Controlled Current Distribution by Defected Ground Structures

Seok-Jae Lee,  Hee-Jong Lee,  Won-Sang Yoon,  Sun-Ju Park,  Jongsik Lim,  Dal Ahn,  Sang-Min Han,  

pp.-

Publication Date:2010/11/23

Online ISSN:2188-5079

DOI:10.34385/proc.52.4FA4-3

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Summary:
From the various design requirements in microwave research area, innovative transmission line architectures have been researched for photonic bandgap structures (PBGs), electromagnetic bandgap structures (EBGs), defected ground structures (DGSs), and metamaterials [1-2]. Among the technologies, the DGS has been researched as the most popular transmission line model. Because the DGS can be modelled by analytical approaches and designed on various design shape [1, 3], the unique characteristics have applied to many kinds of microwave devices such as microwave amplifiers [4], dividers [5], filters [6] and so on. However, even though the DGS has merits to reduce microwave devices, it has difficulty in a resonator design. In case of antennas, a few approaches have been tried by merging the DGS transmission line technologies [7-10]. In this paper, a circular polarized (CP) antenna design is presented from a control of resonant characteristics by the DGS. The resonance can be controlled by adjusting current distribution on a patch antenna by using a DGS slot on a ground plane. The antenna polarization consists of timevariant current direction on the patch conductor. A circular polarized antenna need to require both bandwidths of an impedance bandwidth (BW) corresponding to the VSWR and a CP BW corresponding to the axial ratio (AR). The CP antenna design suffers from the CP BW which is more complicated design parameters such as input impedance, feedline structures, antenna shape, and phase differentiation. Because a large AR is induced by asymmetry of the current distribution between two orthogonal current, the larger one can be controlled by DGS. In this paper, current control on the DGS circular patch antenna is proposed. The controllability of the DGS antenna can enhance a new antenna design methodology.