A 50:1 Bandwidth Tightly Coupled Dipole Array With Short-Circuit Resonance Suppressing Surface

The Tightly Coupled Dipole Array (TCDA) provides broadband performance. This is achieved due to the interaction between coupled dipoles. However, the traditional tightly coupled antenna has the problem of short circuit resonance, which leads to the limitation of its broadband performance. To address this issue, this brief proposes the incorporation of a resistive frequency-selective layer and a novel frequency-selective surface to reduce the influence of short-circuit resonance on the broadband performance of tightly coupled antennas. Additionally, the array antenna exhibits a thin profile with a size of 1/
$20{\lambda }_{L}$
. The proposed single-polarization tightly coupled antenna achieves a continuous impedance bandwidth of 51:1 (0.33-17 GHz) with VSWR < 3 across the entire frequency range, and VSWR < 5 when scanning down to 45° in the E/H plane. Moreover, the proposed dual-polarization ultrawideband tightly coupled antenna achieves a continuous impedance bandwidth of 50:1 (0.33-16.5 GHz) with VSWR < 3 across the entire frequency range, and VSWR < 4 when scanning to 60°.