Microstrip unequal Wilkinson power divider with 1:11 division ratio

In this paper, a 1:11 unequal microstrip Wilkinson power divider (WPD) is presented. Power division is a necessary function in most of the wireless/wireline communication systems. To design 1:11 WPD using an easy-to-fabricate microstrip technology, microstrip line having a very high characteristic impedance (Z(c)) value of 315 omega is needed. Realization of this value is impractical because too thin line is required. Defected ground structure (DGS) provides the hosting microstrip line with high inductance and modest capacitance values simultaneously. As a result, very high impedance could be implemented using practical lines. Novel analytical calculation method is developed to compute Z(c) of microstrip line loaded with DGS. It is found that circular-patterned DGS could be used to realize the required microstrip line. The designed WPD is fabricated and measured at centre frequency (f(c)) equals 1GHz. The measurements of insertion and reflection losses of the fabricated circuit as well as the isolation between the output ports are in a good agreement with the simulated responses of the designed circuit.