An Omnidirectional CPW Leaky-Wave Antenna With Steering Conical Beam

Abstract

This paper proposes a planar omnidirectional leaky-wave antenna with 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 are 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.