This paper proposes a hybrid algorithm based on Genetic Algorithm (GA) and Evolution Strategy (ES). The GA is not successful in searching an optimal solution in the view point of convergence speed and solution quality. The ES has the risk of being trapped in a local minimum. The hybrid algorithm is composed of GA and ES in order to make up for these defects of GA and ES. The procedure of search...

A low profile patch antenna for GPS application is here proposed and analyzed. The radiating structure consists on a square patch with 8 slits introduced on each side and on the corners to reduce the overall dimensions. The circular polarization is obtained by quadrature feeding the patch with two pins placed symmetrically on the two main axis. The 90° phase shift is obtained by a 90° microstri...

Abstract: To obtain free-space antenna factors (AFs) of hybrid antennas, two different calibration procedures have been used: one with ground reflection (ANSI method) and one without ground reflection (free-space arrangement). AFs of 38 antennas are compared in an overlapping frequency range. Also the standard deviation has been calculated over the frequency range to show the precision of the m...

Abstract. We consider the exact controllability of a hybrid system consisting of an elastic beam, clamped at one end and attached at the other end to a rigid antenna. Such a system is governed by one partial differential equation and two ordinary differential equations. Using the HUM method, we prove that the hybrid system is exactly controllable in an arbitrarily short time in the usual energy...

M. S. A. S. Rizk and G. Moms, “New class of broadband hybrid mode horn,” presented at Inst. Elec. Eng. Colloquium on Antenna Bandwidth Extension Techniques, London, Oct. 28, 1985. H. C. Minnett and B. MacA. Thomas, “A method of synthesizing radiation patterns with axial symmetry,” IEEE Trans. Antennas Propagat., vol. AP-14, pp. 654-636, Sept. 1966. N. Marcuvitz, Waveguide Handbook. New York...

The finite element method (FEM) has the potential of simulating plasma waves seamlessly from the core to the vacuum and antenna regions. We explored the possibility of using a versatile FEM solver package, COMSOL, for lower hybrid (LH) wave simulation. Special care was paid to boundary conditions to satisfy toroidal symmetry. The non-trivial issue of introducing hot plasma effects was addressed...

In this paper we propose the optimization of patch size for a fractal hybrid antenna that can be used in GPS applications. This project is about two different models namely sierpinski gasket fractal antenna and Koch rectangular fractal antenna. A fractal antenna in general is characterized by space filling and self-similarity properties. These fractal shaped antennas have their own unique chara...

During this decade, the design of small-size wireless communication devices was key topic in the field of communication engineering. The design of miniaturized antenna is an important parameter to reduce the overall size of the wireless communication devices. Many approaches have been proposed to design the miniaturized antennas. Recently, fractal antenna geometry has been employed to design th...

Current drive using RF waves has been proposed as a means to reduce the tearing fluctuations responsible for anomalous energy transport in the RFP. A traveling wave antenna operating at 800 MHz is being used to launch lower hybrid waves into MST to assess the feasibility of this approach. Parameter studies show that edge density is a major factor in antenna/plasma coupling. Gas puffing near the...

A single cell scenario consisting of a multiantenna base station and several single antenna mobile stations is considered. An intermediate non-regenerative multi-antenna relay station is used to support the bidirectional communications. In such a scenario, the required data rates for upand downlink are typically different which is considered by introducing asymmetric rate requirements. A transm...