obtained from the generalized Z T-chart in Eq. (29). Therefore, the computerized generalized Z T-chart can provide accurate results indeed, and it can be used effectively in analysis and design of BCITLs.
CONCLUSIONSA graphical tool, called a generalized T-chart, for analysis and design of BCITLs is developed in this article. It is a generalized version of the standard T-chart developed for solving CCITL problems. Because of the fact that the CCITL is a special case of the BCITL when Z 0 ϩ ϭ ͑Z 0 Ϫ ͒*,, which means that the generalized T-chart can be reduced to the standard T-chart when the condition is satisfied. The use of the generalized T-chart is found to be similar to that of the standard T-chart. A computerized software is developed and employed in this study. It is found that the software provides accurate results. Further applications of the generalized T-chart will be investigated in the future. 3. D. Torrungrueng and C. Thimaporn, Application of the T-chart for solving exponentially tapered lossless nonuniform transmission-line problems, Microwave Opt Technol Lett 45 (2005), 402-406. 4. D. Torrungrueng and C. Thimaporn, Applications of the ZY T-Chart for nonreciprocal stub tuners, Microwave Opt Technol Lett 45 (2005), 259 -262. 5. D. Torrungrueng, A. Wongwattanarat, and M. Krairiksh, On the magnitude of the voltage reflection coefficient of terminated reciprocal uniform lossy transmission lines, Microwave Opt Technol Lett, in press. 6. D.M. Pozar, Microwave engineering, 3rd ed., Wiley, Hoboken, NJ, 2005.ABSTRACT: In this article, techniques to generate circularly polarized waves for a quad-unit are investigated. The quad-unit is offset-fed by an open rectangular ring. It has been shown that both 3-dB axial ratio and 10-dB return loss bandwidths can be achieved up to 11%. With a large ring, we have a stable maximum beam at the bore-sight direction. In experiments, it can provide a gain of 7 dBic at 5.5 GHz.
