Effect of lateral walls on the propagation characteristics of finite-width conductor-backed coplanar waveguides

The connection of the side planes of finite-width conductor-backed coplanar waveguide (FW-CBCPW) to the ground through lateral walls suppresses the undesired microstrip-like (MSL) mode and provides a wide frequency range over which singlemode propagation occurs. The leakage or resonance phenomena of the higher-order modes can be avoided, if the distance separating the lateral walls is carefully designed.