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° to +78°, in the second one from -40° to +20° and in the new RH band (12.6- 13.4 GHz) from +22° to +54°. 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.