Browsing by Author "Chan, Chi-Hung"

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DUAL-BAND COUPLER UNIT AND DUAL-BAND COUPLER THEREOF AND RECEIVER THEREOF
(2010-12-16)
Kuo, Jen-Tsai
;
Chiou, Yi-Chyun
;
Chan, Chi-Hung
A dual-band coupler unit is provided. The dual-band coupler unit includes a first coupled line, a second coupled line, a short transmission line, a first transmission line, and a second transmission line. The first coupled line and the second coupled line are substantially in parallel with each other, and are substantially of the same length. One end of the short transmission line is connected to one end of the first coupled line, and the other end of the short transmission line is connected to one end of the second coupled line. One end of the first transmission line is connected to the other end of the first coupled line, and one end of the second transmission line is connected to the other end of the second coupled line.
New Miniaturized Dual-Band Rat-Race Coupler With Microwave C-Sections
(2009)
Chiou, Yi-Chyun
;
Kuo, Jen-Tsai
;
Chan, Chi-Hung
;
電信工程研究所
;
Institute of Communications Engineering
Based on microwave C-sections, rat-race coupler is designed to have a dual-band characteristic and a miniaturized area. The C-section together with two transmission line sections attached to both of its ends is synthesized to realize a phase change of 90 degrees at the first frequency, and 270 degrees at the second passband. The equivalence is established by the transmission line theory, and transcendental equations are derived to determine its structure parameters. Two circuits are realized in this presentation; one is designed at 2.45/5.2 GHz and the other at 2.45/5.8 GHz. The latter circuit occupies only 31% of the area of a conventional hybrid ring at the first band. It is believed that this circuit has the best size reduction for microstrip dual-band rat-race couplers in open literature. The measured results show good agreement with simulation responses.