Coplanar waveguide feed to the hemispherical DRA

In this communication, several coplanar waveguide topologies to the hemispherical DRA are presented. It is seen that the inductive and the circular-loop CPW feed configurations offer the flexibility to excite the fundamental [TE.sub.111] resonant mode of the hemispherical DRA close to the source free resonant frequency, due to the presence of metallization in the coupling region. Dual-band behavior is observed with the capacitive feed due to the DRA and slot resonant modes, which are displaced with respect to the unperturbed modes due to the uninterrupted slot. The radiation characteristics of the antenna are also explained. Index Terms--Capacitive, coplanar waveguide (CPW), circular-loop, dielectric resonator, inductive.