Photonic crystal waveguides with inner metal coated posts at millimeter-wave frequency range

Metallic waveguides are popular at microwave and millimeter-wave frequency range because of their low propagation loss. They need a bend-waveguide at bending corner since they are not easy to bend. The photonic crystal (PC) with 2D metallic rods is lmown as a waveguide without bending loss. Though the PC waveguides can construct bend path easily, bend direction is usually parallel to one plane because of their structures. This paper presents a PC waveguide with inner metal-coated posts connected with metal rods that can easily fabricate bend waveguide toward two directions. From our calculation, propagation loss due to the metal is around 1.5-2dB/m (at 30GHz). Though the loss is larger than conventional metallic waveguide, the PC waveguide is easy to fabricate and reconstruct the propagation path.