A novel bandwidth enhancement technique for a compact right/left-handed (CRLH)transmission line (TL) based antenna
A novel composite right/left-handed (CRLH) transmission line (TL) based metame- trial antenna with wide bandwidth is presented in this paper. The motivation behind the work was the increase in demand for compact metamaterial antennas for applications that require wide bandwidths [1]. Enhancement...
| Main Authors: | , , |
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| Format: | Conference or Workshop Item |
| Language: | English |
| Published: |
2011
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/11880/ http://irep.iium.edu.my/11880/ http://irep.iium.edu.my/11880/1/A_novel_bandwidth_enhancement_technique_for_a_compact_right-left-handed.pdf |
| Summary: | A novel composite right/left-handed (CRLH) transmission line (TL) based metame-
trial antenna with wide bandwidth is presented in this paper. The motivation behind the work
was the increase in demand for compact metamaterial antennas for applications that require wide
bandwidths [1]. Enhancement to the bandwidth of the antenna is achieved by incorporating two
additional capacitances, in both, the shunt and series arm of the CRLH TL unit cell equivalent
circuit. The additional capacitance in the series arm of the CRLH TL unit cell was added in
parallel to the left-handed capacitance, CL, by which an increase in the total series capacitance
is achieved. This was done by means of a cap in the form of the metal-insulator-metal (MIM),
which was introduced on a layer below the radiating patches. The additional capacitance in the
shunt arm of the CRLH TL unit cell was added in series to the right handed capacitance, CR, by
which a decrease in the total shunt capacitance is achieved. This was done by means of a parallel
plate that is being introduced on a layer between the vias and the ground plane of the unit cell.
The proposed unit cell consists of the original mushroom structure (which is made up of a patch
and a via connecting the patch to the ground plane), a cap and a parallel plate. Analysis of the
dispersion characteristic of the proposed unit cell reveals a reduction in dispersion as compared
to the unit cell without the two additional capacitances. This factor contributes to the increase
in the bandwidth of the structure. The antenna con¯guration is in the form of a 2 £ 2 patch. A
comparison made between the bandwidth of the proposed CRLH TL antennas with the conven-
tional CRLH TL antenna, shows an increase in bandwidth from 9.2% to 18.5%. The proposed
antenna is a tri-band and its length, width and height at the ¯rst resonant frequency are ¸0=26,
¸0=26 and ¸0=27, respectively; where, ¸0 is the free space wavelength. |
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