ABSTRACT A novel design approach to dual‐band multimode resonant microstrip annular sector patch antenna (MASPA) with enhanced backfire gain and low profile is proposed. The design innovatively combines a quadruple mode resonant patch with an annular sector reflector, exploiting hybrid radial and circumferential modes to achieve an adjustable dual‐band ratio (DBR) and wide impedance bandwidths. A prototype antenna is designed and fabricated for validations on a 4‐mm‐thick air substrate. It achieves fractional bandwidth of 21% at 3.0GHz‐band and 11% at 5.9GHz‐band, with measured backfire gains enhanced to 2.1 and 7.9 dBi at the two bands, respectively. The design approach achieves enhanced backfire gain and wider bandwidth with fewer elements. Further measurements of the antenna mounted at different positions on a bulky metal plate verify the robustness of the proposed design approach.
Zhou et al. (Wed,) studied this question.