A Three-Band Substrate Integrated Waveguide Leaky-Wave Antenna Based on Composite Right/Left-Handed Structure

In this communication, the design and implementation of a three-band substrate integrated waveguide (SIW) leaky-wave antenna (LWA) based on the composite right/left-handed (CRLH) structure is presented. CRLH unit cell of the proposed antenna is composed of two adjacent interdigital slots with two vias between them. Two CRLH bands along with a new right-handed (RH) band between them are achieved through this structure. The first CRLH band (7.1–10.75 GHz) is balanced and the second one (15.1–21.75 GHz) is unbalanced with 0.25-GHz stop band. Beam scan angle in the first CRLH band is from $- 78^\circ $ to $+ 78^\circ $ , in the second one from $- 40^\circ $ to $+ 20^\circ $ and in the new RH band (12.6–13.4 GHz) from $+ 22^\circ $ to $+ 54^\circ $ . Antenna radiation efficiency in the first CRLH band is about 90%. Simulated and measured results are compared and there is a good agreement between them.