Design of SIW Filtering Power Dividers Based on Fractal Metamaterial Slotted Resonators

With the development of new generation wireless communication technology, microwave devices are developing towards miniaturization and integration. Power dividers are important components of the transmitter, their size and performance can influence the quality of communication systems greatly. Therefore, in order to decrease the size of the power dividers and to reduce component size, this paper proposes several substrate integrated waveguide (SIW) power dividers based on fractal metamaterial slotted resonators. First, planar geometrical fractals such as the Minkowski fractals, Hilbert fractals and von Koch fractals have been applied in the SIW structure as slots. Due to the slow wave effects, the size of the proposed SIW can be reduced compared with conventional SIWs. Then by loading slotted resonators, the filtering characteristics can also be achieved. To verify the performance of the proposed structure, three SIW power division filters have been designed based on these proposed fractal metamaterial slotted resonators. The input and output of the power division filters are connected with tapered microstrip lines with the port characteristic impedance of 50 ohms. As the full-wave simulated results show that the proposed power division filters can achieve a filter band from 9 GHz to 11.9 GHz with the in-band S11 better than −10 dB. Based on the electric field distribution, it can also be observed that the size has been reduced. Further improvements have been achieved. Our proposed structures are easy to manufacture and can be applied in the modern wireless communication circuits and systems.