A Microstrip Leaky-Wave Antenna with Scanning Beams Horizontal to the Antenna Plane

A leaky-wave antenna with horizontal scanning beams and broadside radiation is presented on the periodically modulated microstrip. The horizontal radiation is realized by periodically etching a set of resonant open-ended slots on the ground plane. Dispersion diagrams and Bloch impedance are first analyzed to investigate the propagation and radiation characteristics of the periodic structure. Subsequently, shunt matching stubs are installed aiming to obtain seamless beam scanning property through the broadside. Finally, a prototype is implemented as verification of the presented antenna. Results of the simulations and measurements agree well with each other, indicating the elimination of the open-stop band effect and the horizontal radiation beams. The fabricated antenna exhibits a beam range from -62° to +34°, and provides a maximum measured gain about 14.6 dBi at 10 GHz.