A simplified dual-band rat-race hybrid for arbitrary power division ratio with only single shunt stub

作者:He Qing*; Shen Junyu; Liu Qiang; Li Jiuchao; Liang Liming
来源:Journal of Electromagnetic Waves and Applications, 2013, 27(16): 2101-2109.
DOI:10.1080/09205071.2013.832396

摘要

A planar, simplified, dual-band rat-race hybrid with arbitrary power division ratio is presented. It is accomplished by inserting only single additional shunt stub in the conventional structure and modifying the lengths and characteristic impedances of the arms. Using rigorous even- and odd-mode analysis, the explicit closed-form equations for this hybrid are derived. Based on the standard microstrip technology, the relationship between the realizable power-split ratios and the frequency ratio is investigated. As a generalized design, it is found that traditional rat-race hybrid and some previous compact structures are special cases of the proposed hybrid. With this method, a prototype operating at 1/3.5GHz with 7.96dB power division ratio is designed, fabricated and measured. The validity of this design has been proved by the consistency of the simulation and measurement results.