SIW TE₁₀/TE₃₀ Mode Circularly Polarized Leaky-Wave Antenna With Dielectric Resonator

In this letter, the substrate-integrated waveguide (SIW) TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub>/TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">30</sub> mode broadband circularly polarization (CP) leaky-wave antennas (LWAs) are proposed. Initially, the surface current distribution characteristics of the SIW fundamental mode (TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub>) and the higher-order TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">30</sub> mode are analyzed, and the CP mechanism of the transverse asymmetric cross-shaped slot is explored. Then, a pair of orthogonal modes of the dielectric resonator (DR) is excited through slot magnetic coupling to enhance CP radiation. Meanwhile, the unit cell loaded with DR increases the attenuation constant, thereby enhancing the gain. Additionally, the transverse asymmetric cross-shaped slot effectively suppresses the open-stopband (OSB) for both unit cells. The SIW TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> and TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">30</sub> mode LWAs have achieved CP radiation with beam scanning of 53° and 43° in 27 GHz to 40 GHz (38.8%) and 30 GHz to 40 GHz (28.6%), respectively. Notably, the SIW TE<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">30</sub> mode LWA has a more compact size. Finally, the correctness of the proposed approach is verified through the fabrication of prototypes and measurements.