Millimeter waveband semisymmetrical groove guide resonators

As an alternative to the classical waveguides, such as the H-waveguide and the rectangular waveguide, the groove waveguide has been used at millimetre wavelengths for the last couple of decades. Most of these properties are attributed to the open sides of the guide, which reduce the wall losses. This article describes a semisymmetrical groove guide resonator that is designed and analyzed analytically, numerically, and experimentally. The numerical simulations are performed via a powerful time-domain simulator based on the finite-difference, time-domain (FDTD) method. Both Cartesian- and cylindrical-coordinate FDTD packages are developed and used for the simulations. The purpose in using cylindrical-coordinate FDTD is to calibrate Cartesian-coordinate FDTD and to see the error introduced due to discretization. A measurement setup with an adjustable support platform in the frequency range of 20-40 GHz is used in the experiments.