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For the simulation of rectilinearly moving conductors across a magnetic field, the Galerkin finite‐element method (GFEM) is generally employed. The inherent instability of GFEM is very often addressed by employing streamline upwinding/Petrov–Galerkin (SU/PG) scheme. However, the SU/PG solution is known to suffer from distortion at the boundary transverse to the velocity and the remedial measures suggested in fluid dynamics literature are computationally demanding. Therefore, simple alternative schemes are essential. In an earlier effort, instead of conventional finite‐difference‐based approach, the numerical instability was analysed using the Z‐transform. By employing the concept of pole‐zero cancellation, stability of the numerical solution was achieved by a simple restatement of the input magnetic flux in terms of associated vector potential. This approach, however, is restricted for input fields, which vary only along the direction of the velocity. To overcome this, the present work proposes a novel approach in which the input field is restated as a weighted elemental average. The stability of the proposed scheme is proven analytically for both one‐ and two‐dimensional cases. The error bound for the small oscillations remnant at intermittent Peclet numbers is also deduced. Using suitable numerical simulations, all the theoretical deductions are verified. [ABSTRACT FROM AUTHOR]

A well‐known property of the Z transform is the differentiation in z‐domain property, which states that if X(z) ≡ Z{x[n]} is the Z transform of a sequence x[n] then the Z transform of the sequence nx[n] is Z{nx[n]}=−z(dX (z)/dz). It is generally believed that the regions of convergence (ROC) for the two Z transforms are the same. It is shown that this is not true in the general case where X(z) is not rational and an example, in which the ROC is different for X(z) and Z{nx[n]}, is given. [ABSTRACT FROM AUTHOR]

In this article, we propose a mapping method in which the system function of filter in z-domain is founded by discrete-time domain techniques as well as by chain-scatte ring matrices of various transmission-lines is derived to fulfill a dualbandpass microwave filter based on equal-length nonuniform coupled lines. A dualband filter with the desired bandwidth and low insertion loss is recognized by cascading bandpass and bandstop filters. The five-order Butterworth bandstop filter, which uses a coupled-serial-shunted lines structure, causes the implantation and correct placement of the bandstop filter. The wide-band bandpass filter is implemented by the five-order Chebyshev Type II band-pass filter, which uses serial lines and shunted stubs lines configuration. The design process is finished by using optimization algorithms to tune the values of characteristic impedances of each transmission-line section. Experimental results significantly agree with the theoretical values. Measurement shows that the 3 dB passband widths are about 20% for the frequency of 2.45 GHz and 10% for the frequency of 5.25 GHz. The insertion loss is about 0.831 dB at the frequency of 2.38 GHz and 1.873 dB at the frequency of 5.216 GHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 210–215, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22075 [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]