N-Port Equal/Unequal-Split Power Dividers Using Epsilon-Near-Zero Metamaterials

In this article, a type of multiport power divider is proposed based on the concept of epsilon-near-zero (ENZ) metamaterials. An arbitrarily shaped ENZ metamaterial comprising a dielectric impurity is connected to N waveguides, and the incident power can be efficiently delivered to output waveguides, with transmitted fields being exactly equal in both amplitude and phase for output branches. Hence, the proposed power divider allows a balanced power allocation independent on its geometrical symmetry. This design philosophy can further be extended to generic dividers with arbitrary power division ratios by modifying the widths of the output waveguides. The experimental verification is carried out in waveguide-emulated ENZ structures. The fabricated eight-way equal-split divider is measured with an average insertion loss of 0.6 dB, a transmission amplitude imbalance of 0.7 dB, and a phase imbalance of 10°, over the 10-dB return-loss bandwidth from 5.35 to 5.56 GHz. The ten-way unequal-split divider with two different groups of outputs is also prototyped, providing a custom-designed power division ratio.