Powder Core Dielectric Waveguides

A powder-filled surface of a led groove in the teflon substrate has been demonstrated as a dielectric waveguide at 94 GHz. Guide wavelengths measured for combinations of guide dimensions and powders agree within 10% of values predicted by Marcatili 's approximate theory. Attenuation constants of 0.2 to 0.3 dB/cm were measured for barium tetra-titanate.