A dielectric waveguide for propagating electromagnetic signals comprises a cladding member (102) extending a length between two ends (104). The cladding member is formed of a first dielectric material. The cladding member defines a core region (114) that extends through the cladding member along the length of the cladding member. The core region is filled with a second dielectric material having a dielectric constant value that differs from a dielectric constant value of the first dielectric material. The cladding member has an oblong cross-sectional shape, and the core region has a circular cross-sectional shape.
