In this paper, a novel accurate Schiffman-type (S-type) section design approach is presented for microstrip line Wilkinson power divider. S-type section replaces straight 90° transmission line with compact circuit size and easy fabrication, isolation condition between two output ports is also maintained in microstrip line structure. Mathematical equations for S-type section are derived from even- and odd-mode equivalent circuit analysis, and several selected examples have been proved that: through adjusting the even- and odd-mode characteristic impedances and their electrical lengths of S-type section, proposed Wilkinson power divider provides perfect matching in microstrip line structure; in other words, S-type section could provide self-compensation in microstrip line structure, no extra compensation structure is needed. In experiment, one circuit was fabricated, and experimental results showed good agreement with theoretical results.
2016 by The Institute of Electronics, Information and Communication Engineers