A Multilayered SIW-Based Circularly Polarized CRLH Leaky Wave Antenna

Abstract

In this article, a multilayered circularly polarized (CP) leaky-wave antenna (LWA) is proposed, based on the composite right/left-handed (CRLH) transmission line concept. The proposed design is composed of a substrate integrated waveguide (SIW) structure and its multilayered unit cell consists of H-shaped interdigital (ID) slots on the top with a truncated patch, sandwiched between the two substrates. Circular slots are introduced periodically on the ground plane to achieve wideband circular polarization. Proposed CRLH SIW-based LWA shows the capability of continuous beam scanning from −38° to +71° within the frequency range of 7.6–10.6 GHz while maintaining good circular polarization in the frequency range of 8.3–10.6 GHz. The peak gain of the proposed LWA is 10 dB and the average radiation efficiency is 86.1% over the complete impedance bandwidth. The measured results of the fabricated prototype are in good agreement with the simulated ones. The proposed antenna can be used for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula> -band radar and satellite applications.