X-band composite right/left-handed leaky wave antenna with large beam scanning-range/bandwidth ratio

A novel composite right/left-handed (CRLH) transmission line cell (TLC) based on a substrate integrated waveguide is proposed, which can be used for a leaky wave antenna for achieving large beam scanning-range/bandwidth ratio. Compared with previous CRLH TLCs, the proposed one has a narrower fast wave region where the propagation constant β changes from -k₀ to +k₀. An X-band leaky wave antenna (LWA) has been designed and fabricated and measurements are presented. Both simulated and experimental results show that the developed LWA has a narrow fractional bandwidth of 26% (from 8.3 to 10.8 GHz) while having a continuous wide beam scanning range of -65° to +54°.