In this manuscript, the use of dielectric rod waveguide antenna (DRW) with an embedded planar lens is proposed as a highly directional alternative to an electrically large hyper-hemispheric silicon lens for emission at millimeter and sub-millimeter wave frequencies. DRW antennas radiate properly if only the fundamental mode is excited to the structure. Since photomixer-based terahertz sources excite many modes, single-lobe radiation patterns are obtained only for lower frequencies of their potential working band. The use of embedded planar lenses is proposed for rectifying the wavefront phase and suppressing such higher-order modes in DRW, allowing an ultra-wideband operation.
antenna; antenna emitter; dielectric rod waveguide; embedded dielectric lenses; high power terahertz; photomixer; thz