A planar end-loaded dipole phased array with enhanced bandwidth and wide-angle scan

摘要

A bandwidth-enhanced wide-angle scanning phased array based on planarend-loaded dipole elements is designed and analyzed in this article. Initially,the phased array is designed based on wideband wide-beam dipole elements,which are placed in a hybrid artificial structure composed of surface waveguide(SWG) and high-impedance surface (HIS). An additional resonance causedby surface-wave propagation in the SWG is generated close to the dipoleresonance. The dual-resonance mechanism improves the impedance bandwidth.Then, in order to enhance the array active reflection performance, theHIS is adopted to reduce the coupling between array elements which is causedby the excited surface waves. Besides, the SWG-HIS hybrid structure has azero-phased reflection in the phased array operation band, which contributesto the wide-angle scan. The total dimension of the proposed eight-elementphased array is about 3.24 λ_0 × 0.675 λ_0 (λ_0 is the free-space wavelength at4.5 GHz). The phased array shows a main-beam scan up to ±60° with a realizedgain higher than 8.8 dBi and a total efficiency higher than 84% in anactive reflection band of 4.35 ～ 4.85 GHz.