Transversely Slotted SIW Leaky-Wave Antenna Featuring Rapid Beam-Scanning for Millimeter-Wave Applications

Loading effects of radiating discontinuities have been explored to increase the phase constant' frequency sensitivity of leaky-wave antennas (LWAs), based on which a quasi-uniform transversely slotted substrate integrated waveguide LWA featuring rapid beam-scanning and its hexagonal array have been proposed and investigated for millimeter-wave applications. The design concept is simply based on the use of a short period of unit cells and a long transverse slot with a sharp inductive reactance, and it has been theoretically elaborated and effectively validated by both full-wave and circuit-based simulations. A taper design with -25 dB Taylor amplitude distribution is implemented for the proposed LWA to have a low sidelobe radiation. For practical system applications, a hexagonal array consisting of six proposed LWAs is developed to provide an omnidirectional coverage in the azimuth plane while remaining the rapid frequency-driven beam-scanning in the elevation plane. Both the measured and simulated results are in an acceptable agreement with respect to the LWA block and the associated hexagonal array in terms of circuit and radiation performances. The proposed antenna will be a good candidate to be applied for prospective millimeter-wave systems such as autonomous driving and flying.