Dual-Polarized Wide-Angle Scanning Phased Antenna With Element Beam Broadening and Parasitic Sidelobe Suppression

This letter presents a dual-polarized planar phased array antenna incorporating dual-dielectric layers and quasi-defected ground structures loading to enable wide-angle beam scanning. Cylindrical dielectric blocks positioned beneath each dipole element, together with a perforated wide-angle impedance matching layer placed above the array, effectively broaden the active element pattern beamwidth from 55° to 126° while enhancing active impedance matching performance. Quasi-defected ground structures are employed not only to secure the cylindrical dielectric blocks mechanically but also to mitigate surface wave coupling. These structures facilitate a uniform electric field distribution across the array aperture, thereby eliminating parasitic sidelobes. An 8 × 8 prototype was fabricated and measured. The array achieves ±60° scanning coverage in both principal planes over the frequency range of 2.1 GHz to 2.5 GHz (17.4% bandwidth), with active voltage standing-wave ratio (VSWR) maintained below 2.2 throughout the scan range. Measurement results demonstrate 1.2 dB gain recovery at large scan angles, sidelobe levels suppressed below –8.2 dB, and cross-polarization levels better than –34 dB. The proposed design is modular, scalable, and well-suited for applications in radar and wireless communication systems.