Resonant lenses as building blocks for advanced narrow-band integrated receivers

Paper describes the electromagnetic performance of compact-size dielectric lenses typically used as building blocks for integrated lens antennas operating at the microwave to optical ranges. Three configurations of lenses are studied, namely: multi-shell spherical, extended hemielliptical, and shaped ones. Although lenses are usually considered as wideband devices whose operation principles are based on the Fresnel laws, under certain circumstances the modal (resonant) features of the aforementioned lenses can become dominant and significantly affect their focusing and collimating capabilities. In most scenarios excitation of internal resonances is an unwanted phenomenon. Nevertheless, we demonstrate that it can be used to design hybrid-type resonant-lens integrated receivers with enhanced sensitivity achieved thanks to exploitation of both optical and modal features of the lenses.