The analysis of general axially symmetric antennas with a coaxialfeed line by the method of lines

The use of the method of lines in the analysis of various circular antennas-circular patch antennas and various forms of monopoles is proposed and substantiated. The antennas considered are fed by coaxial lines. Impedance/admittance transfer procedures are developed, which allow to calculate the antenna input impedance by a successive transfer from the aperture through the different sections. The described relations are also useful for other applications     

Efficient analysis of periodic structures

An algorithm which allows the analysis of optical periodic structures with a very large number of periods with minimum numerical problems is presented, For this purpose the stable impedance transfer is combined with Floquet's theorem. Numerical results for a Bragg grating with up to 20000 periods are presented featuring the very moderate numerical effort     

Analysis of rectangular waveguide discontinuities by the method oflines

An efficient analysis of discontinuities in the rectangular waveguide is presented using the method of lines with one-dimensional discretization. As the line numbers in the incoming and outgoing waveguides are automatically correctly chosen in the method of lines, relative convergence is avoided. Scattering parameters for the E-plane step discontinuity are determined and an equivalent circuit for the diaphragm, the displacement, and a step with diaphragm is presented     

Efficient and accurate modeling of planar anisotropic microwavestructures by the method of lines

A new algorithm for the analysis of planar microwave structures with anisotropic substrates is proposed and substantiated. This algorithm is based on generalized transmission-line (GTL) equations, which are developed here for numerical algorithms. For the purpose of analysis, two different modal matrices for the discretized transverse electric and magnetic fields are calculated. Furthermore, impedance/admittance transformation formulas are developed with the help of the GTL equations for longitudinal sections and general junctions. Crossed discretization lines are used in the latter case. The materials are assumed to be biaxial or specific anisotropic. Special algorithms are developed for junctions consisting of more than two waveguides in the cross section and for bends. The proposed algorithm is verified by numerical results     

The method of lines for the analysis of planar waveguides withfinite metallization thickness

The method of lines is extended to calculate waveguide structures with finite metallization thickness. The normally used range of metallization thickness is not a limit for the method. Particularly when calculating small or moderate thicknesses, it is possible to derive the dispersion constant with only one computed result. When using the optimal edge parameter, P_opt, for that computation, the deviation from the exact dispersion constant is less than 0.5%. The advantage of the method of lines is that only small line numbers are necessary. Hence, the computing time is very small     

New approach for the analysis of cylindrical antennas by the methodof lines

A new approach for the analysis of cylindrical antennas with the method of lines (MoL) is described. The open structure is modelled with absorbing boundary conditions (ABCs). Current distributions and especially input impedances of a dipole are in good agreement with literature. Conductor loss is taken into account     

A COST 240 benchmark test for beam propagation methods applied toan electrooptical modulator based on surface plasmons

Modeling of a waveguide polymer electrooptic (EO) modulator based on a resonant excitation of surface plasmons was used as a benchmark test for several beam propagation methods (BPMs). Wave-optical analysis of the structure is presented, and the results of four implementations of three numerical modeling methods are mutually compared and discussed     

The method of lines for the analysis of lossy planar waveguides

The method of lines is extended to calculate the losses of waveguide structures. Ohmic losses in metallizations (with frequency-dependent, extremely high dielectric constants) and dielectric losses are simultaneously considered. Despite the high ratios of the dielectric constants of the metallizations and the dielectrics, the analysis and numerical treatment are carried out accurately. Using nonequidistant discretizations the results are computed efficiently, and an approximate value of the propagation constant close to the exact value is found by extrapolation. The phase constant deviates less than 0.5%. The attenuation may deviate up to 2%. The advantages of the method of lines are a small computation time and, due to the analytical solutions of the fields in one direction, a very good approach to the fields inside the strip as well as to the strong fields directly adjacent at the edges. The results for a single microstrip line are shown and compared with those of other authors