Planar Leaky-Wave Antenna Featuring Wideband Fixed-Beam Radiation and Tailorable Directional Angle for Millimeter-Wave Applications

Inspired by the well-known power/energy leakage phenomenon between an unshielded grounded coplanar waveguide (GCPW) and its neighboring parallel-plate waveguide (PPW), a class of simple, low-cost, and planar leaky-wave antennas (LWAs) exhibiting wideband fixed-beam radiation and tailorable directional angle are systematically investigated and developed for millimeter-wave applications. The capability of providing wideband fixed-beam radiation (desired) and the inflexibility of altering the beam’s directional angle (undesired) are first studied and revealed concerning a uniform GCPW LWA. Then, to freely tailor its beam angle while maintaining such wideband radiation, three effective engineering techniques, i.e., using periodic GCPW/PPW and altering the PPW’s pitch angle, have been proposed and separately examined. Two LWAs using part of these techniques are modeled, fabricated, and measured for demonstration purposes. Simulated and measured results are in good agreement, and both exhibit the expected wideband fixed-beam radiation and tailorable directional angle. Due to the merits of simple configuration, well-behaved electrical behaviors, and good design flexibilities, our proposed GCPW LWAs may be potentially deployed for millimeter-wave systems such as 60-GHz point-to-point communications.