Arbitrary waveguide connector based on embedded optical transformation

Arbitrary connector for waveguides of different cross sections is proposed and designed theoretically based on the embedded optical transformation theory. First, the general expressions of constitutive tensors of the metamaterials filled in the connector are derived. Second, there are some full-wave simulations that validate the constitutive tensors derived. The results show that the connector with metamaterials inclusions with designed constitutive parameters can fulfill the reflectionless transmission of electromagnetic waves between waveguides of different cross sections. Finally, connectors of several forms are investigated parametrically, and two sets of constitutive tensors that can be physically achieved by existing metamaterials are gotten. It is believed that this study provides a feasible way to fulfill the efficient transmission of electromagnetic waves between waveguides of different cross sections.