Dual-Beam Frequency-Scanning Leaky-Wave Antenna Based on Composite Slow-Wave Waveguide

In this research, we propose a dual-beam frequency-scanning leaky-wave antenna that utilizes a composite slow-wave waveguide. The composite slow-wave waveguide is created by integrating double-layer symmetrical spoof surface plasmon polaritons structures on both sides of the half-mode substrate integrated waveguide to support a composite slow-wave mode. To achieve the desired dual-beam radiation pattern, periodic circular patches are placed on both sides of the composite slow-wave waveguide. These circular radiation patches are coupled electromagnetically with the slow-wave waveguide. Additionally, a rectangular copper patch is introduced in the antenna design to reduce interference between the two radiation beams. Using simulation, we demonstrate that the proposed leaky-wave antenna achieves continuous beam-scanning within an operating frequency range of 9–11 GHz, with angles of 54° and 55° for the upper and lower beams, respectively.