Analysis and simulation of a 6.7 GHz coaxial Bragg reflector

A coaxial line periodically loaded by circular disks on the inner conductor is designed to act as Bragg reflector in the 4.0–10.0 GHz frequency range. This is achieved by placing 10 disks (0.35 cm thick and 6.22 cm in diameter) equally spaced by the periodic distance of 1.8 cm on a coaxial waveguide with inner and outer diameter of 6.90 cm and 4.22 cm. Analytical discussion followed by 2D and 3D computer simulations demonstrate a bandgap of 5.6 GHz centered at the 6.7 GHz design frequency