Transmission behavior of microwaves through photonic-crystal waveguides fabricated by stereolithography

Millimeter order photonic crystals with a diamond structure were fabricated by using stereolithography. Titania-silica ceramic powders were dispersed into the epoxy lattice to control the dielectric constant. A perfect photonic band gap was formed in the 10.2-13.8 GHz rangc. Various waveguides consisting of air cavities were formed in the photonic crystal, and the transmission behavior of microwaves was studied. The L-type and T-type waveguides showed high transmitting and splitting performance. The L-type waveguide showed high transmitting behavior, whereas the T-type waveguide showed splitting behavior in the band-gap frequency range.