A Broadband Tightly Coupled Antenna Array with Over 100:1 Bandwidth and Extremly Low Profile Based on a Resistive High-Pass Filter

In this paper, an exceptionally broadband antenna array with an extremely low profile based on tightly coupled antenna arrays is reported. To increase the operating bandwidth without compromising the unit-cell profile, a high-pass filter based on a resistive frequency selective surface is employed. It can absorb the reflected power and prevent short circuits at lower frequencies. The proposed antenna array unit-cell features a simulated bandwidth of 111.5:1, maintaining an active VSWR less than 3.29 across the entire frequency band. The total height of the proposed array unit-cell is only O.44Ahigh. Furthermore, the simulated total efficiency exceeds 23% across the entire frequency band, averaging around 46%. The minimum efficiency matches well with the numerical analysis, substantiating the effectiveness of our proposed design.