Circumferentially conformal slot array antenna and its Ka‐band multibeam applications

Abstract

A standing‐wave slot array covered with a two‐layer dielectric slab based on substrate integrated waveguide (SIW) technology, which is circumferentially conformed to a cylinder, is designed, fabricated and measured at Ka‐band. The radiating part consists of seven slotted cylindrical SIWs, each of which has four‐element longitudinal slots. Several such slot arrays fed by Rotman lenses are grouped on a cylinder along the circumferential direction to cover a 2D field of view. The microstrip Rotman lens is employed as the beamforming network with seven input ports, which can generate a corresponding number of beams to cover −35° to 35° along 1D ( E ‐plane). Another dimension ( H ‐plane) is covered from −52° to 52° with four beams generated by the slot arrays group. A prototype antenna is fabricated, the measured results demonstrate its ability of scanning over a 2D field of view with multiple beams. This type of multibeam conformal antenna is a good candidate for high‐speed vehicles or communication base stations requiring electronic beam‐scanning capabilities and considering conformal reasons.