• Journal of Advanced Navigation Technology
• /
• v.13 no.5
• /
• pp.720-725
• /
• 2009

This paper proposes a modified Wilkinson power divider using a zero-degree composit right/left-handed(CRLH) transmission line to obtain a isolation between ports. A zero-degree CRLH transmission line, which has a total electrical length of zero, consists of a RH(Right-Handed) transmission line of a negative phase characteristic and a LH (Left-Handed) transmission line of a positive phase characteristic. To validate a value of zero-degree CRLH transmission line, the electrical lengths of RH and LH transmission line select $-30^{\circ}$ and $+30^{\circ}$ and a 2-way Wilkinson divider designed, we are measured S21 of -3.3dB, S11 of -27.5dB and S23 of -25dB at 1GHz center frequency. These characteristics are same the conventional divider using RH transmission line.

• Journal of Advanced Navigation Technology
• /
• v.17 no.2
• /
• pp.196-201
• /
• 2013

In this paper, a dual-mode balanced filter with symmetric coupled composite right/left-handed transmission line is introduced. Unlike the other symmetric structure, this configuration has the ability to operate under both common- and differential-mode excitation. These properties are achievable through providing physical short circuit by means of ground vias at the center of each unit-cell along the symmetry plane of the structure. Because the CRLH unit-cells are operated under both common- and differential-mode excitation, we implemented a balanced filter using these properties. To validity these features, a five-cell four port coupled CRLH-TL is simulated, fabricated and measured and the obtained performances agree with the simulation results under both common- and differential-mode excitation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.25 no.2
• /
• pp.156-163
• /
• 2014

In this paper, a compact circularly polarized metamaterial patch antenna using cross aperture-coupled feed is proposed. The CP antenna utilizes the -1 mode that is induced by the composit right-left handed(CRLH) transmission line. Since the -1 mode has the same properties with the $TM_{010}$ mode of the conventional patch antenna, the circular polarization(CP) can be realized. If two orthogonal modes are excited with $90^{\circ}$ phase difference, the CP property can be obtained. In order to obtain two orthogonal modes and $90^{\circ}$ phase difference, 4 mushroom structures having the shape of square are employed. The width and length of the cross aperture are optimized through the design algorithm. The fabricated antenna is based on RT/duroid5880 substrate and the total area of the 4 mushroom is $0.25{\lambda}_0{\times}0.25{\lambda}_0$. The center frequency of the LHCP(Left-Handed Circular Polarization) antenna is measured as 1.622 GHz and circular polarization bandwidth(3 dB) is measured as 3 MHz. The center frequency of the RHCP(Right-Handed Circular Polarization) antenna is measured as 1.609 GHz and circular polarization bandwidth (3 dB) is measured as 3 MHz, respectively. The measured radiation efficiency of LHCP antenna is 61.1 % and the measured radiation efficiency of RHCP antenna is 54.5 %.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.14 no.6
• /
• pp.117-124
• /
• 2015

In this paper, a new kind of wideband, low-loss composite right/left-handed (CRLH) transmission line (TL) and a Wilkinson power divider are presented. The TL is composed of a parallel meander inductor and a series cutting capacitor based on coplanar waveguide (CPW) structure. The power divider is designed by substituting the CRLH-TL into the conventional transmission line. The experiment results show that the TL has a good agreement with the desired results, exhibiting the return losses under 12 dB from 8.4 GHz to 34.4 GHz. The operating frequencies of the power divider are 12.05 GHz to 13.15 GHz and 16.50 GHz to 19.30 GHz, respectively. The 20 dB bandwidths are 8.9 % and 17.9 %, respectively. Typical experimental measurements are conducted and compared with the simulated results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.9
• /
• pp.1034-1041
• /
• 2012

In this paper, a compact circularly polarized metamaterial patch antenna using the -1 mode that is induced by the composit right-left handed(CRLH) transmission line is proposed. Basically, since the -1 mode is the same properties with the +1 mode of the conventional patch antenna, the circular polarization(CP) is realized. If two orthogonal -1 modes are excited with $90^{\circ}$ phase difference, the CP property can be obtained. In order to obtain two orthogonal modes and $90^{\circ}$ phase difference, 4 mushroom structures having the shape of triangle are employed and the inter-digital gaps are optimized, respectively. The fabricated antenna is based on RT/duroid5880 substrate and the total area of the 4 mushrooms is $0.161{\lambda}_0{\times}0.161{\lambda}_0$. It is confirmed that the center frequency of the proposed antenna is measured as 2.845 GHz and it operates from 2.830 GHz to 2.850 GHz. In addition, the antenna maintains the CP property from 2.842 GHz to 2.847 GHz at the peak gain and the measured radiation efficiency is 46 %.