Optimum transmitter receiver ratio for maximum wireless energy transfer

Due to high demand of using cordless mobile device, the interest in wireless energy transfer (WET) has been growth intensively. This paper presented a method to obtained optimum transmitter receiver ratio for maximum performance of WET system using different initial antenna size at various distance. An optimized algorithm has been developed to determine the optimum ratios that yield the highest wireless transfer efficiency (WTE) at near field communication (NFC) frequency, 13.56MHz. 30mm × 30mm single square loop antenna is used as initial size of both transmitter and receiver using FR4 with operating distance = 50mm. Operating distance and initial size of the antenna will be varied and the effect to the WTE will be studied using Matlab, verified using Microsoft Studio CST. At distance = 50mm and initial size of the antenna = 30mm × 30mm, optimum transmitter to receiver ratio equal to 1:3 is obtained. The pattern of optimum transmitter receiver ratio between Matlab and CST has met an agreement. This research limited to integer transmitter receiver ratio used only and no decimal number being involved in magnify the transmitter size

Analysis of Concentric Split Ring Square Element for Broadband Reflectarray Antenna

An investigation of phase variation and phase range of concentric split ring square element for broadband reflectarray antenna is presented in this paper. This is realized by exploiting the physical geometry of three element shapes namely square element, concentric ring square element and concentric split ring square element. Modifying the current distribution of basic concentric ring square element, leads to a less steep phase variation and also the bandwidth performance. An analysis of frequency response is described and analysed. The physical interpretation of the elements is also discussed. The proposed antenna element effectively covers two frequency operations (13.44 GHz and 18.36 GHz) in Ku-band range. Bandwidth broadening is achieved by introducing the ring square combination of element and the practical phase range is achieved through the use of RF 35 (thickness = 1.524 mm) as the substrate. The new concept of split initiates to a wider bandwidth (up to 67.6 %) for the antenna and can applied to any two frequency operations of Ku-band applications

Development of Ray Tracing Algorithms for Scanning Plane and Transverse Plane Analysis for Satellite Multibeam Application

Reflector antennas have been widely used in many areas. In the implementation of parabolic reflector antenna for broadcasting satellite applications, it is essential for the spacecraft antenna to provide precise contoured beam to effectively serve the required region. For this purpose, combinations of more than one beam are required. Therefore, a tool utilizing ray tracing method is developed to calculate precise off-axis beams for multibeam antenna system. In the multibeam system, each beam will be fed from different feed positions to allow the main beam to be radiated at the exact direction on the coverage area. Thus, detailed study on caustics of a parabolic reflector antenna is performed and presented in this paper, which is to investigate the behaviour of the rays and its relation to various antenna parameters. In order to produce accurate data for the analysis, the caustic behaviours are investigated in two distinctive modes: scanning plane and transverse plane. This paper presents the detailed discussions on the derivation of the ray tracing algorithms, the establishment of the equations of caustic loci, and the verification of the method through calculation of radiation pattern

Thermodynamic and kinetic stability. Properties of micelles and vesicles formed by the decanoic acid/decanoate system

The dialysis of micellar and vesicular systems, through a cellulose acetate membrane permeable only to monomer surfactant, has been investigated for the system sodium decanoate/decanoic acid as a function of pH, in pH regions where micelles (pH 9) or vesicles (pH 7.5) are present. The results provide data that are helpful in establishing the thermodynamic state of the systems and the interplay of the relevant equilibrium and kinetic considerations. Additionally, the kinetics of spontaneous formation and destruction of vesicles when subjected to a pH-jump perturbation have been studied. Changes are rapid, taking place over a time scale of a few seconds