A Wideband ACS-Based Pattern-Reconfigurable Antenna with Coupled Patches and Defected Ground Loading

Abstract

A wideband pattern-reconfigurable antenna (PRA) integrating an asymmetric coplanar strip (ACS), coupled patches, and defected ground structure (DGS) loading is presented. The ACS provides the basic tilted-beam radiation, while the coupled patches and DGS provide complementary impedance-matching contributions in the upper and lower portions of the operating band, respectively. Their interaction with the original ACS response establishes three resonant responses that collectively broaden the matched band. The loading structures and two-PIN switching scheme are jointly designed to realize broadband radiation pattern reconfiguration, maintaining two selectable tilted-beam states across the wide operating band through a single feeding port. A prototype is fabricated and achieves a measured common −10 dB impedance bandwidth of 57.6%, covering 4.2–7.6 GHz. A radiation efficiency above 90% is obtained at the tested frequencies, and the measured radiation patterns generally maintain their overall tilted-beam shapes, with sidelobe levels more than 9 dB below the main beam. The proposed design provides a practical solution for broadband directional wireless applications requiring flexible coverage.