International Journal

The plane wave diffraction by a planar junction consisting of a thick metallic sheet and a lossy double-negative metamaterial slab is studied by using the Uniform Asymptotic Physical Optics approach. This approach assumes the radiation integral as a starting point and uses the physical optics surface currents as sources to be integrated. The integral is manipulated by taking advantage of useful ap

The problem of the plane -polarized electromagnetic wave scattering by flat pre-fractal impedance strips' gratings is examined. For this purpose, a mathematical model in the form of the first kind singular integral equation system is modified for correct usage. Considerable attention is focused on the asymptotic model of the -polarized electromagnetic wave scattering by sparsely filled grating, wh

The spectral and energy characteristics of the tunable thin planar dielectric resonator with the movable metal mirror are researched. It is found that the high--polarized whispering gallery modes (WGMs) are effectively excited in such a resonator by the dielectric waveguide. A mode set of the tunable thin planar dielectric resonator depends on the presence of an air gap in its design. Changing the

Multiplexer design is a challenging task due to the high number of variables involved, raising the difficulty as the numbers of filters increase. Numerical computing tools provide a suitable environment to evaluate topologies and technologies before starting the long journey to the device. A direct scattering matrix solution for a star-junction multiplexer, based on the circuit theory, is presente

The paper presents a highly efficient GaN-based synchronous buck converter suitable for switching in the lower GHz range. The module includes a very compact 2-stage GaN half-bridge converter MMIC (monolithic microwave integrated circuit) for low parasitic inductances between switches and drivers and a hybrid output network with core-less inductors to avoid ferrite losses. At 1 GHz switching freque

This paper presents the design and analysis of a rectangular slot antenna for producing a directional radiation pattern over a wide bandwidth of 6?9 GHz. A basic wideband slot antenna is designed for the desired frequency band by microstrip offset feed technique. This antenna is then loaded with a superstrate and a reflector, both made of conducting sheets. Analogous to a three-element Yagi antenn

In this paper, the design and analysis of a complementary Sierpinski Knopp fractal antenna are presented. It is realized by applying the Sierpinski Knopp space-filling curve on the basic square monopole antenna. The performance metrics of the antenna such as (reflection coefficient), voltage standing wave ratio, radiation pattern, gain and current distribution at resonant frequencies are analyzed

In this paper, a compact circularly polarized quadrifilar antenna with planar inverted-F antenna (PIFA) elements is presented. The proposed antenna consists of four PIFA elements and a Wilkinson divider-based feed network fabricated on FR-4 substrate ( = 4.4, loss tangent = 0.02, thickness = 1.6 mm). The total size of the antenna is 120 × 120 × 13.2 mm. Impedance matching with a reflection coeffic