In this paper a statistical model of the excitation of a conjugate-matched two-wire transmission line in a lossy half space by an electromagnetic (EM) wave is developed. The EM field, radiating in the air, is obliquely incident to the interface defined by the lossy medium and air. Three different orientations of the transmission line for horizontal and vertical polarization of the EM field are examined. The objective is to derive analytic formulas for the probability density function (pdf) and cumulative distribution function (cdf) of the induced near-end and far-end voltage magnitudes in each case, taking into consideration the statistical behavior of the amplitude of the incident electric field vector and the angle of incidence as well. Consequently, the mean values as well as the typical deviation values are presented and the contribution of each one of the parameters is discussed in detail. Finally, a chi-square goodness-of-fit test is applied in order to fit the distribution of the induced voltage with one of the known distributions.

The finite-difference time-domain (FDTD) method is applied to the probe-fed square patch microstrip antenna stacked a parasitic patch for high gain. The input impedance, the directivity, the far field radiation patterns and the near field distributions are calculated and the relation between the antenna structure and the high gain is investigated The calculated input impedance and radiation patterns agree well with the experimental values. When the size of parasitic patch is nearly equal to the fed patch and the distance between the fed patch and the parasitic patch is about a half wavelength, the maximum gain of 9.43 dBi is obtained. In this case, the region between the fed patch and the parasitic patch forms a resonator. Then, the amplitude of current distribution on the parasitic patch becomes large and its phase is opposite to the current on the fed patch. The amplitude of electromagnetic fields of the space between the patches are increased.

Modeling of long range propagation of collimated wavepackets poses some major difficulties with the conventional FDTD scheme. The difficulties arise from the vast computer resources needed to discretize the entire region of interest and the accumulation of numerical dispersion error. As a means for circumventing these difficulties, the moving frame FDTD approach is in this work. In this approach, the computational grid size is limited to the order of the pulse length, and it and moves along with the pulse. The issues discussed in conjunction with this method are those of numerical dispersion, which is shown to be reduced substantially compared with the stationary formulation, numerical stability, and absorbing boundary conditions at the leading, trailing and side boundaries, Numerical results of pulsed beam propagation in both homogeneous and plane stratified media are shown, and the capability of the method is demonstrated with propagation distances exceeding the order of 10⁴ pulse lengths.