Nonradiative dielectric (NRD) rotman lens with gap-coupled unidirectional dielectric radiator (UDR)

In this paper, nonradiative dielectric (NRD) rotman tens with a gap-coupled unidirectional dielectric radiator (UDR) has been presented. Design parameters of UDR such as length of resonator and distance of gap are determined using an equivalent circuit model of an evanescent NRD guide. Experimental prototype is fabricated and measured around 38 GHz. The result shows a good agreement with theory. Finally, total beam pattern of NRD rotman lens of multi-beam feed has been obtained using a measured pattern of UDR and army factor of NRD rotman lens. The obtained beam pattern shows remarkably suppressed side lobe.