Design of a substrate integrated waveguide modified R-KR lens for millimetre-wave application

In this study, a new type of substrate integrated waveguide (SIW) beamforming network (BFN) based on the principle of the modified R-KR lens has been proposed and experimentally verified. Through the detailed analysis of such a structure, a prototype lens with 15 input ports is implemented together with an SIW slot array antenna at 30 GHz, which is able to cover a wide angle of (59, 59) with its 3 dB beam-width. The measured radiation efficiencies of the lens excited at different ports range from 21.6 to 40.8 . This type of BFN takes the advantages of low profile, low cost and high performance, and may be applied to millimetre-wave mobile communications and radars with beam switching technology.