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This paper presents an integrated approach to taking a frequency-domain simulation problem into the discrete time domain, based on z transforms. The ideas are illustrated with free space, the Drude pole, and perfectly matched layer (PML) conversion examples, for both leapfrog time stepping and simultaneous time stepping. Numerical results for various perfectly matched layer methods are given. We then present a two-dimensional scattering example in which the conversion from frequency to discrete time is carried out. Numerical results are presented and compared with results from a Method-of-Moments formulation. [ABSTRACT FROM PUBLISHER]

The impulse-invariance z transform method has been used to discretize frequency-dependent dielectric functions for FDTD simulations. This paper reviews, generalizes, and compares several methods for improving the accuracy of this process. A slightly novel curve-fitting approach is presented for the dielectric function of silver. [ABSTRACT FROM AUTHOR]

This is an introductory paper on z-transform-based methods for electromagnetic transient simulations of power systems. Since the theory of the z-transform was originally developed for the analysis of time series data defined at equidistant time steps, simulation models developed using z-transforms can readily be used in electromagnetic transient simulations based on the same time step. First, this paper briefly introduces the basics of the z-transform, and then applications to electromagnetic transient simulations of power systems are reviewed. [ABSTRACT FROM AUTHOR]

The bilinear transformation is employed to represent the trapezoidal-rule integrator in the Z domain. This formulation, in conjunction with the representations of transmission-line elements in the Z domain, leads to the transmission-line configuration that is eligible for a microwave integrator. A microstrip circuit is implemented to verify the feasibility of the technique. Except for the lower-frequency band, the experimental results are in good agreement with the theoretical values of the trapezoidal-rule integrator. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 822–825, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21485 [ABSTRACT FROM AUTHOR]

A wideband differentiator is implemented by using nonuniform transmission lines. To utilize the transfer function of a differentiator developed in a study of discrete signal processing (DSP), we formulate the scattering characteristics of equal-length electrical transmission line sections in the Z domain. A uniform line shunted with a two-section stub is obtained to emulate the transfer function of a stable second-order recursive differentiator. A microstrip circuit is implemented to verify this novel method and experimental results are in good agreement with theoretical design parameters. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 226–228, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10877 [ABSTRACT FROM AUTHOR]