Propagation characteristics and power transmission in shielded microstrip lines with double negative medium

In this paper, the shielded microstrip lines with double negative medium are investigated using the rigorous spectrum domain approach. The Chebyshev polynomials with edge singularity are used as current basis and the results agree with the reference in which trigonometric functions with edge singularity are used. The dispersion properties are studied with different case sizes. Field distributions imply significant difference from that of the double positive materials. Power transmission provides physical meaning for the different modes as frequency changing. The complex mode does not carry any net power and there are two types of propagating modes: forward and backward. Finally, the impact of the number of terms of the current basis on result accuracy is investigated. It shows that relatively small number of terms gives satisfactory accuracy.