Tilted Beam Formation Using Parasitic Loop-Based Plates

Abstract

An antenna system that forms a high-gain tilted beam is discussed. This system is composed of a single-feed antenna with a wide beam and two parasitic loop-based plates, ${{\rm P}_{\rm l}}$ and ${{\rm P}_{\rm u}}$ (two-plate system), where the widths of the strip loops differ. The electromagnetic wave from the fed patch experiences a phase shift through ${{\rm P}_{\rm l}}$ and ${{\rm P}_{\rm u}}$ . It is predicted that the two-plate system creates a tilted beam whose tilt angle is larger than a conventional one-plate system (where plate ${{\rm P}_{\rm u}}$ is absent). Full-wave analysis [finite-difference time-domain (FDTD) analysis] confirms this prediction using a patch antenna as the fed antenna. In addition to radiation pattern analysis, the gain and VSWR are investigated. Subsequently, the two-plate system is successfully applied to the formation of a tilted dual beam.