Two types of dual-band bandpass filtering Wilkinson power divider with microstrip composite resonators

A dual-band bandpass filtering Wilkinson power divider is newly introduced in this paper. A 2-degree bandpass filter topology with dual-band performance replaces two λ/4 transmission lines in Wilkinson power divider design. There are two different design methods for proposed power divider application: Type I and Type II. Design equations and circuit realization are summarized in detail. Considering better isolation performance and compact circuit size, Type II is preferred in this paper. In experiment, a Type II Wilkinson power divider with central frequencies of 2.4 GHz and 5.2 GHz is designed and fabricated using microstrip lines and open-/short-stubs. There is good agreement between the simulated and measured results.