A general transformation for compact waveguide coupler by using homogeneous media

A general transformation is proposed to design the compact waveguide coupler with homogeneous media. By dividing the coupling region into several triangle blocks and engaging the transformation, material inhomogeneity of the coupler can be eliminated, and thus the device only requires homogeneous and anisotropic media. Also, it is found that the electromagnetic field in the coupling region can be controlled artificially and the field in the two waveguides is little influenced. Thus, much freedom and flexibility is provided in the design of waveguide coupler. Besides, the general transformation can also be extended to design waveguide bender with homogeneous media. Furthermore, Full wave simulation based on finite element method is performed to verify the performance of the waveguide coupler.

► In this paper, a general transformation is proposed to design the compact waveguide coupler with homogeneous media.
► As long as the coupling region is divided into several triangle blocks (two, three or four blocks) and general transformation is employed, material inhomogeneity of the device can be eliminated, and thus the device only requires homogeneous and anisotropic media.
► Numerical results indicate that the electromagnetic field in the coupling region can be controlled artificially and the field in the two waveguides is little influenced.
► As a consequence, much freedom and flexibility is provided in the design of waveguide coupler.
► Besides, our general transformation can also be extended to design waveguide bender with homogeneous media.
► Full wave simulation based on finite element method is performed to verify the performance of the waveguide coupler.