An Omnidirectional CPW Leaky-Wave Antenna With Steering Conical Beam

This letter proposes a planar omnidirectional leaky-wave antenna with a steering conical beam and stable radiation through the broadside on the periodically modulated coplanar waveguide (CPW). The radiation characteristics of the leaky CPW cells are investigated according to different-shaped open-end slots and various widths of the substrate layer. Then, the omnidirectional conical radiation beam is obtained by etching exponentially tapered open-end slots on the CPW ground parts and modifying the width of the substrate layer properly. Under the frequency balanced condition, a pair of additional series inductive slots is etched on the modulated CPW to balance the Bloch impedance and suppress the open-stop band effect. An antenna demonstration is designed as verification. The measured results validate the simulated results experimentally, confirming the conical beams in the H-plane and the wide-angle beam scanning of −60° to 17° in the E-plane.