High-Scanning-Rate Leaky-Wave Antenna With Simple Structure and Low Profile

This letter proposes a novel high-scanning-rate leaky-wave antenna (LWA) characterized by a simple structure and low profile. The high-scanning rate and high-order harmonic suppression principles of the proposed meandering structure are first analyzed. Two types of high-scanning-rate LWAs are designed to verify the principle. Longitudinal elliptical and butterfly-shaped slots are etched onto the meandering substrate integrated waveguide to radiate linearly and circularly polarized beams, respectively. The open stopbands for both antennas are effectively suppressed. Prototypes are fabricated and measured. The measured results indicate that the linearly polarized antenna achieves a scanning range of 140° and a scanning rate of 9.2, while the corresponding parameters of the circularly polarized antenna are 90° and 11.3, with the axial ratios lower than 3 dB.