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By shunting a susceptance at the middle of the branch of a conventional Wilkinson power divider, the size can be reduced and the harmonic components can be suppressed. Further, miniaturization can be achieved by optimal layout of the internal area of the conventional power divider. In this article, simple design methods to implement miniaturized Wilkinson power dividers with harmonic suppressions are presented. To validate the design methodology, two power divider prototypes are optimally designed and examined from electromagnetic simulations and experiments. As compared to conventional types, the circuit sizes of the demonstrators are effectively reduced to 15.6 and 24.98%, respectively, and the spurious suppressions are over 20 dB at the desired harmonic frequencies. Meanwhile, the mechanisms of spurious suppression are studied herein. The achieved performance simply confirms the presented design methodology. [ABSTRACT FROM AUTHOR]

A laddered spiral phase plate excited by a microwave antenna to generate a vortex electromagnetic wave is studied. By replacing the continuous spiral phase plate with several planar metal plates, a ladder spiral phase plate that is easily built is designed. When the spiral phase plate is slightly tilted away from the xoy-plane to approximate the parabola plate, and it is further excited by a microstrip patch antenna, different orbital angular momentums are obtained. The presented scheme provides a convenient and simple approach to generate a vortex wave at microwave frequencies. [ABSTRACT FROM AUTHOR]

ReaxFF molecular dynamics (MD) simulations are performed to study high-temperature pyrolysis of toluene under microwave heating. It is observed that the temperature of the reaction system under microwave heating has a rapidly rising stage, which is similar to the phenomenon of thermal runaway often appeared in reactions under microwave heating. Simulations indicate that the consumption rate of toluene and generating rates of H2and CH4obtained under microwave heating are always lower than those obtained under conventional heating at the early stage. Analyses of the pyrolysis of toluene show that ReaxFF MD simulations can provide an efficient way to study chemical reactions under microwave heating. [ABSTRACT FROM PUBLISHER]