• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.10
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• pp.1091-1096
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• 2009

Some closed-form expressions for circuit parameters are derived based on the equivalent circuits for the resonant MTM-TL(open and short). The lumped series resistance and shunt conductance, which explain radiation effects of a unit cell may be found by |$S_{11}$|(simulated or measured) with open and short terminations, respectively. The EM-simulated results, circuit-simulated results(obtained using extracted circuit parameters) and measurement results are shown to be in good agreement.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.8
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• pp.1-7
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• 2008

In this paper, we propose a lossy MTM transmission line unit cell and retrieve the parameter values related with radiation effects. Based on this unit cell model, we plot dispersion diagrams and analyze resonance conditions. We also discuss the input impedance or admittance behavior when we terminate the load as open or short. Then, we examine the quality factor and return loss bandwidth. We also design a very compact unit cell antenna using the provided lossy MTM-TL model. The results based on EM simulations and measurements are shown to be in good agreement with those based on circuit simulation.

• Journal of electromagnetic engineering and science
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• v.12 no.4
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• pp.280-286
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• 2012

The conventionally classified waves are reclassified in this paper, including the waves associated with metamaterial (MTM) transmission lines. Various types of guided waves in periodic structures are analyzed for 1D Composite Right/Left Handed (CRLH) transmission lines (TL). In addition, dispersion diagrams for 1D CRLH, RH, and LH TLs are presented in terms of radiation conditions. We have refined the design equations of the conventional 1D CRLH TL and proposed a condition to realize the desired phase shift and its slope per unit cell. This condition has been applied to the conventional Wilkinson power divider and realized into MTM added $90^{\circ}$ hybrid coupler. Based on the 10 dB return loss and the $90{\pm}10^{\circ}$ phase shift, the bandwidths of the MTM added $90^{\circ}$ hybrid coupler are 82.25% and 103.5% against the conventional 23% and 52.5%, respectively.