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This paper investigates the structural evolution in a magnetic fluid microstrip under external magnetic fields parallel to the strip surface. It is shown that as the field strength increases, the structure evolves from an originally monodispersed state to a disordered magnetic chain state, and then to a one-dimensional ordered structure of chains. For the ordered structure state, the chain spacing is reduced with an increase in field strength, because more columns form under higher fields. Thus, a tunable one-dimensional ordered structure can be achieved in magnetic fluid films under parallel magnetic fields. The manipulations of the tunability of the ordered structure under various control parameters, such as the sweep rate of the magnetic field, the fluid concentration, and the strip width, are also discussed. [ABSTRACT FROM AUTHOR]

A very compact wireless local area network antenna using meander striplines in three low-temperature co-fired ceramic layers is designed and fabricated in this study. This chip antenna has a small volume of only 3.2 × 1.6 × 2 mm3. The measured radiation bandwidths (voltage standing wave ratio ≤ 2) of 2.45 and 5.8 GHz are 110 and 150 MHz, and the peak gains of the two bands are −1.6 and 2.7 dBi, respectively. The resonant frequencies can easily be tuned by adjusting the inner coupling between different patterns and the length of the striplines. Besides, no via-hole was used in this structure, which guarantees the easy fabrication and high production. [ABSTRACT FROM AUTHOR]

A single layer compact size Swastik-shaped microstrip patch antenna is designed and studied. The antenna is designed to cover the frequency band designated for IEEE802.11 b for WLAN applications. The proposed antenna has simulated return loss of -29.5dB at 5.8GHz frequency. The peak gain of this antenna at resonance frequency is 1.6dB. The antenna is probe feeded. The Ansoft HFSS is employed for the antenna design. [ABSTRACT FROM AUTHOR]

A small H-shaped microstrip patch antenna (MPA) with enhanced bandwidth is presented. The H-shaped antenna is first studied by a transmission line model and then is fully analyzed with a MoM code. A stacked patch configuration is proposed to increase the narrow bandwidth, radiation efficiency and directivity. The stacked H-shaped MPA is studied using Chu's fundamental limit for electrically small antennas. [ABSTRACT FROM AUTHOR]

In this paper, we report on the results of an investigation into dual-mode operation of microstrip triangular patch resonators and their applications for designing dual-mode bandpass filters. It has been found theoretically that the dual modes can result from the rotation and superposition of a fundamental mode. The characteristics of the dual modes and their mode splitting are described. The applications of this new type of dual-mode microstrip patch resonator in the design of microwave planar filter are presented. A circuit model for operation of this type of filter is proposed. Two- and four-pole filters of this type are demonstrated for the first time. Both theoretical and experimental results are presented. [ABSTRACT FROM AUTHOR]

Quasi-TEM propagation, appropriate for a linearly tapered microstrip line is modeled, and known microstrip impedance behavior is approximated directly. The telegraphist's equations and the resulting ABCD matrix are solved in terms of Airy functions. The theoretical model, which includes conductor and substrate losses, has been verified experimentally. [ABSTRACT FROM AUTHOR]

This article describes the average power handling capability (APHC) of multilayer microstrip lines, including the effect of mismatch at the terminations. The data presented herein are validated by considering an example of a 12-W monolithic microwave integrated circuit power amplifier fabricated using multilayer low-loss microstrip technology. The calculated value of APHC for a 50-Ω line of a 75-μm-thick GaAs substrate is 1445 W at 10 GHz, whereas the corresponding value for a multilayer microstrip that has 10-μm-thick polyimide is only 44 W. At 40 GHz, these values are reduced by a factor of 2. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 385–395, 2001. [ABSTRACT FROM AUTHOR]

An approach is developed for 3D microstrip discontinuities using the finite element method (FEM) and the perfectly matched layers (PML). It is shown that iterative solvers are not suitable for this problem since the matrix equations from the PML-used FEM modeling are rather ill-conditioned and lead to a very slow or nonconvergent result. A newly developed package SuperLU of the sparse LU decomposition solver is incorporated into our developed approach running on a PC-based parallel platform. Various implementation techniques are detailed. Numerical experiments clearly show that the developed approach is reliable, efficient, and suitable for modeling 3D microstrip discontinuities. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 38–47, 2001 [ABSTRACT FROM AUTHOR]

A quarter-wavelength-coupled filter with prescribed frequency response is presented which uses a novel configuration of series-cascaded microstrip lines as its resonating components. Design equations are obtained from ABCD parameters, with approximations taken to account for the double resonance characteristics of the filter's constituent networks. Experimental and theoretical results agree closely. [ABSTRACT FROM AUTHOR]

The mode-matching technique is used to quantify the inaccuracy, especially at high frequencies, of an equivalent network model of a stripline T junction, with a branch-line coupler used as a representative example of devices consisting of T junctions. Experimental results are also presented to verify the accuracy of the mode-matching technique. [ABSTRACT FROM AUTHOR]

In this article the method of lines is extended to solve the electromagnetic problems in cylindrical coordinates. It is shown that this method is both simple and effective in treating the calculation of cylindrical microstrips, striplines, and other related problems. [ABSTRACT FROM AUTHOR]