In this paper a CPW-fed slot antenna for wideband application was designed and simulated. In order to examine the performances of this antenna a prototype was designed at frequency 2.4 GHz and simulated with various width of slot antenna in both sides for input impedances matching and simulated by IE3D software package of Zeland. The simulation result of bandwidth is 1.65 GHz (2.1{3.75 GHz) which covers the standard frequency of IEEE 802.11 b/g (2.4{2.4835 GHz) and Wimax (2.3{3.6 GHz). With these performances the proposed antenna can be used in wideband applications.

The narrow slot loop antenna and linear slot antenna fed by microstrip line are designed for dual frequency at 2.44 GHz and 5.25 GHz on the standard of IEEE 802.11b/g (2.4{2.4835 GHz) IEEE 802.11j/a (5.15{5.35 GHz) and IEEE 802.16d (5.7{5.9 GHz). These structures are easy to adjust the length of slot antenna for dual frequency band. It can control the higher frequency band around 4.9 GHz to 5.8 GHz by linear slot antenna. Adjusting some parameters of narrow slot loop antenna will influence on the resonance frequency and bandwidth. By using IE3D software [1] the characteristics of antenna are investigated and analyzed including instance input impedance return loss and far field radiation patterns.

This paper presents a testing of three insulators namely solid fluid and gas for choosing the best electric insulators. In order to generate the ozone gas the insulator must be selected in electrode set. Nowadays the insulators do not have the optimal test procedure for getting total efficiency. Therefore in this paper a design of ozone generator is proposed by using the fundamental of electric field stress. The ozone generator is a coaxial cylindrical electric type that has solid insulator in center of glass tube. This solid insulator will be dielectric among the high voltage electrodes. Ozone gas will generate in this air gap. This paper also focuses on the insulator testing of three insulators. It will find the efficiency of 3 insulators and compares them with the density and stress of ozone gas. The experimental results show the performance and ensure the optimal ozone generator design.

This research aims to investigate the efficiency and quality of young rice planting machine which is suitable for the North Eastern part of Thailand. The investigation applies the notions of planting young rice manually by farmers into the design of a battery-driven young rice planting machine. The researcher started with the study of transplanting methods of agriculturists in the North Eastern part and the design principles of young rice planting machine. Next the components were calculated and engineering design was drawn. Then the machine was tested in terms of its efficiency and quality. The data were analyzed in terms of means. The results show that the efficiency of the machine regarding planting performance is 90 % the appearance of the machine functions applications engineering and safety achieve the average point of 3.70 which is considered satisfactory.

This article describes an efficient approach to the implementation of bit-serial lattice wave digital filters based on field programmable gate array (FPGA). In this paper a time schedule of all of the bit-serial two-port adaptors is presented as a bridge between conception and completion. Finally with the satisfying frequency response the filter is successfully tested by both computer simulation and real signal measured from the programmed FPGA.